Digital Equipment Corporation (Digital) developed the DECnet protocol to provide a way for its computers to communicate with one another. DECnet is currently in its fifth major product release called Phase V. DECnet Phase V is a superset of the OSI protocol suite, supports all OSI protocols, and is compatible with the previous release, Phase IV. DECnet Phase IV Prime supports inherent MAC addresses, which allow DECnet nodes to coexist with systems running other protocols that have MAC address restrictions. DECnet support on our routers includes local-area and wide-area DECnet Phase IV routing over Ethernet, Token Ring, FDDI, and serial lines (X.25, Frame Relay, SMDS).
Use the commands in this chapter to configure and monitor DECnet networks. For DECnet protocol configuration information and examples, refer to the "Configuring DECnet" chapter of the Router Products Configuration Guide.
access-list (standard)
To create a standard access list, use the access-listglobal configuration command. Use the no form of this command to delete the entire access list.
access-listaccess-list-number{permit | deny} source source-mask no access-list
Syntax Description
access-list-number
Integer you choose between 300 and 399 that uniquely identifies the access list.
permit
Permits access when there is an address match.
deny
Denies access when there is an address match.
source
Source address. DECnet addresses are written in the form area.node. For example, 50.4 is node 4 in area 50. All addresses are in decimal.
source-mask
Mask to be applied to the address of the source node. Bits are set wherever the corresponding bits in the address should be ignored. All masks are in decimal.
Default
No access list is defined.
Command Mode
Global configuration
Usage Guidelines
In contrast with IP masks, a DECnet mask specification of "all ones" is entered as the decimal value 1023. In IP, the equivalent is 255.
Example
The following example sets up access list 300 to deny packets coming from node 4.51 and permit packets coming from 2.31:
To create an extended access list, use the access-listglobal configuration command. Use the no form of this command to delete the entire access list.
access-listaccess-list-number {permit | deny} source source-mask [destination destination-mask] no access-list
Syntax Description
access-list-number
Integer you choose between 300 and 399 that uniquely identifies the access list.
permit
Permits access when there is an address match.
deny
Denies access when there is an address match.
source
Source address. DECnet addresses are written in the form area.node. For example, 50.4 is node 4 in area 50. All addresses are in decimal.
source-mask
Mask to be applied to the address of the source node. All masks are in decimal.
destination
(Optional) Destination node's DECnet address in decimal format. DECnet addresses are written in the form area.node. For example, 50.4 is node 4 in area 50.
destination-mask
(Optional) Destination mask. DECnet addresses are written in the form area.node. For example, 50.4 is node 4 in area 50. All masks are in decimal.
Default
No access list is defined.
Command Mode
Global configuration
Example
In the following example, access list 301 is configured to allow traffic from any host in networks 1 and 3. It implies no other traffic will be permitted. (The end of a list contains an implicit "deny all else" statement.)
To create an access list that filters connect initiate packets, use the access-listglobal configuration command. Use the no form of this command to disable the access list.
Integer you choose between 300 and 399 that uniquely identifies the access list.
permit
Permits access when there is an address match.
deny
Denies access when there is an address match.
source
Source address. DECnet addresses are written in the form area.node. For example, 50.4 is node 4 in area 50. All addresses are in decimal.
source-mask
Mask to be applied to the address of the source node. All masks are in decimal.
destination
(Optional) Destination node's DECnet address in decimal format. DECnet addresses are written in the form area.node. For example, 50.4 is node 4 in area 50. All addresses are in decimal.
destination-mask
(Optional) Destination mask. DECnet addresses are written in the form area.node. For example, 50.4 is node 4 in area 50. All masks are in decimal.
eq | neq
Use either of these keywords:
eq—item matches the packet if all the specified parts of source-object, destination-object, and identification match data in the packet.
neq—item matches the packet if any of the specified parts do not match the corresponding entry in the packet.
source-object
(Optional) Contains the mandatory keywordsrcand one of the following optional keywords:
eq | neq | lt | gt—equal to, not equal to, less than, or greater than. These keywords must be followed by the argument object-number, a numeric DECnet object number.
exp—stands for expression; followed by a regular expression that matches a string.
uic—stands foruser identification code; followed by a numeric user ID (UID) expression.The argument [group, user] is a numeric UID expression. In this case, the bracket symbols are literal; they must be entered. The group and user parts can either be specified in decimal, in octal by prefixing the number with a 0, or in hex by prefixing the number with 0x. The uic expression is displayed in show displays as an octal number.
destination-object
(Optional) Contains the mandatory keyworddstand one of the following optional keywords:
eq | neq | lt | gt—equal to, not equal to, less than, or greater than. These keywords must be followed by the argument object-number, a numeric DECnet object number.
exp—stands for expression; followed by a regular expression that matches a string.
uic—stands foruser identification code; followed by a numeric user ID (UID) expression. In this case, the bracket symbols are literal; they must be entered. The group and user parts can either be specified in decimal, in octal by prefixing the number with a 0, or in hex by prefixing the number with 0x. The uic expression is displayed in show displays as an octal number.
identification
(Optional) Uses any of the following three keywords:
id—regular expression; refers to user ID.
password—regular expression; the password to the account.
account—regular expression; the account string.
any
Item matches if any of the specified parts do match the corresponding entries for source-object, destination-object, or identification.
See the "Regular Expressions" appendix for a description of regular expressions.
Default
No access list is defined.
Command Mode
Global configuration
Usage Guidelines
Depending upon the arguments you use, you can define access lists in three ways:
Restrict access based on source addresses
Use the source and source-mask arguments only.
Restrict access based on destination addresses
Use the source, source-mask, destination, and destination-mask arguments.
Add filters to further narrow access
Use the source, source-mask, destination, and destination-mask arguments, the eq | neq or any keywords and any or all of the following arguments: source-object,destination-object, and identification.
The following example illustrates an access list for matching all connect packets for object number 27:
access-list 300 permit 0.0 63.1023 eq dst eq 27
The following example illustrates an access list for matching all connect packets except for the object number 17:
access-list 300 permit 0.0 63.1023 neq dst eq 17
The following example illustrates an access list for matching all connect packets where the access identification was SYSTEM:
access-list 300 permit 0.0 63.1023 eq id ^SYSTEM$
The following example illustrates an access list for matching all connect packets from area 1 to object number 27 (27 = VAX/VMS Personal Utility or MAIL) where SYSTEM is the originating user:
The following example illustrates an access list for matching any connect packet and can be used at the end of a list to permit any packets not already matched:
To create a DECnet access group, use the decnet access-group interface configuration command.
decnet access-group access-list-number
access-list-number
Either a standard or extended DECnet access list. A standard DECnet access list applies to source addresses. The value (or values in the case of extended lists) can be in the range 300 through 399.
Syntax Description
Default
No access group is defined.
Command Mode
Interface configuration
Example
The following example applies access list 389 to interface Ethernet 1:
To configure border routers to propagate Phase IV areas through an OSI backbone, use the decnetadvertise global configurationcommand. To disable this feature, use the no form of this command.
decnet advertise decnet-area hopscost no decnet advertise[decnet-area]
decnet-area
Phase IV area that you want propagated.
hops
Hop count to be associated with the route being advertised. Default is 0.
cost
Cost to be associated with the route being advertised. Default is 0.
Syntax Description
Default
Disabled
Command Mode
Global configuration
Usage Guidelines
The output from the show decnet routeEXEC command shows the cost and hop count for routes.
The decnet advertise command is used by border routers for propagating Phase IV areas through an OSI backbone.
The decnet advertise command and the clns route nsap-prefix discard command work together. When a router has DECnet Phase IV/V conversion enabled, any packet with the specified CLNS NSAP prefix causes CLNS to behave as if no route was found. That router then looks up the route to the border router that is advertising the Phase IV route. In turn, the router that is advertising the DECnet Phase IV route converts the packet to Phase V and sends it through the OSI cloud to the border router that is advertising the CLNS discard static route. Once it gets there, the packet is converted back to Phase IV.
The CLNS discard routes are created dynamically when the advertised adjacencies are propagated through the CLNS cloud. When a DECnet interface is disabled, the adjacencies are lost and the CLNS discard route is deleted. The DECnet area routing states are displayed in the output from the show decnet route EXEC command.
Example
The following example shows a partial use of the decnet advertise command:
decnet conversion 49
decnet advertise 4
clns route 49.0001 discard
Related Commands
A dagger () indicates that the command is documented in another chapter.
To set the maximum cost specification value for interarea routing, use the decnet area-max-cost global configuration command.
decnet [network-number] area-max-cost value
network-number
(Optional) Network number in the range 0 through 3. Specified when using Address Translation Gateway (ATG). If not specified, the default is network 0.
value
Maximum cost for a route to a distant area that the router may consider usable; the router treats as unreachable any route with a cost greater than the value you specify. A valid range for cost is from 1 through 1022. This parameter is only valid for area routers. The default is 1022.
Syntax Description
Defaults
network-number: 0 value: 1022
Command Mode
Global configuration
Usage Guidelines
Make sure you have used thedecnet node-type area global configuration command before using this command.
Example
In the following example, the node type is specified as area and the maximum cost is set to 500. Any route with a cost exceeding 500 will be considered unreachable by this router.
To set the maximum hop count value for interarea routing, use the decnet area-max-hops global configuration command.
decnet [network-number] area-max-hops value
Syntax
network-number
(Optional) Network number in the range 0 through 3. Specified when using Address Translation Gateway (ATG). If not specified, the default is network 0.
value
Maximum number of hops for a usable route to a distant area. The router treats as unreachable any route with a count greater than the value you specify. A valid range for the hop count is from 1 through 30. The default is 30 hops.
Description
Default
30 hops
Command Mode
Global configuration
Usage Guidelines
This command is only valid for area routers. Make sure you have issued the decnet node-type area global configuration command before using this command.
Example
The following example sets the router to be a Level 2 router, then sets a maximum hop count of 21:
Use the decnet congestion-threshold interface configuration command to set the congestion- experienced bit if the output queue has more than the specified number of packets in it. A number value of zero or the no form of the command prevents this bit from being set. Use the no decnet congestion-threshold command to remove the parameter setting and set it to 0.
decnet congestion-threshold number no decnet congestion-threshold
number
Number of packets that are allowed in the output queue before the system will set the congestion experience bit. This value is an integer between 0 and 0x7fff. The value zero prevents this bit from being set. Only relatively small integers are reasonable. The default is 1 packet.
Syntax Description
Default
1 packet
Command Mode
Interface configuration
Usage Guidelines
If a router configured for DECnet experiences congestion, it sets the congestion-experienced bit.
Example
The following example sets the congestion threshold to 10:
interface Ethernet 0
decnet congestion-threshold 10
decnet conversion
To allow Phase IV routers (running Software Release 9.1 or higher) to run in a Phase V network and vice versa, enable conversion with the decnet conversion global configuration command. To disable conversion, use the no form of this command.
decnet conversion nsap-prefix no decnet conversion nsap-prefix
Syntax Description
nsap-prefix
Value used for the IDP field when constructing NSAPs from a Phase IV address.
Default
Disabled
Command Mode
Global configuration
Usage Guidelines
To enable DECnet conversion, you must configure both DECnet and ISO CLNS on your router.
DECnet Phase V is OSI-compatible and conforms to the ISO 8473 (CLNP/CLNS) and ISO 9542 (ES-IS) standards. Digital has defined algorithms for mapping a subset of the Phase V address space onto the Phase IV address space and for converting Phase IV and Phase V packets back and forth. This allows a network administrator to support both Phase IV hosts in Phase V networks and Phase V hosts in Phase IV networks.
Our implementation differs from Digital's in how reachability information is advertised. Our implementation allows you to add Phase V support without modifying your existing Phase IV support. It also delays converting packets from Phase IV to Phase V, while Digital's implementation converts as soon as possible.
It is essential that the area you specify in the decnet routingglobal configuration command is the same as the local area you specified with the net router configuration command for the CLNS network.
Make sure that the area you specify in the decnet conversion command is the same as the area you specified for the CLNS network. Also note that the DECnet area is specified in decimal, and the CLNS area is specified in hexadecimal.
The decnet routing command is specified with a decimal address, while the net command address is specified in hexadecimal. In addition, the nsap-prefix specified on the decnet conversioncommand must match one of the NETs for this router.
The following guidelines apply:
Host connectivity across multiple areas is only possible if a Level 2 path exists for which every Level 2 router in the path supports a common protocol: Phase IV or Phase V. If not all routers support both protocols, those routers that do must have conversion enabled.
Host connectivity across a single area is only possible if a Level 1 path exists for which every Level 1 router in the path supports a common protocol: Phase IV or Phase V. If not all routers support both protocols, those routers that do must have conversion enabled.
The Level 2 backbone must have conversion enabled in all Level 2 routers that support an area that needs conversion.
Example
The following example enables DECnet conversion on a router with the area tag xy and Phase IV address 20.401 using an ISO IGRP router:
clns routing
decnet routing 20.401
decnet max-address 600
!
router iso-igrp xy
net 47.0004.004d.0014.aa00.0400.9151.00
!
decnet conversion 47.0004.004d
!
interface ethernet 0
decnet cost 4
clns router iso-igrp xy
Related Commands
A dagger () indicates that the command is documented in another chapter.
To set a cost value for an interface, use thedecnet cost interface configuration command. Use the no form of this command to disable DECnet routing for an interface.
decnet cost cost-value no decnet cost
Syntax Description
cost-value
Integer from 1 through 63. There is no default cost for an interface, although a suggested cost for FDDI is 1, for Ethernet is 4, and for serial links is greater than 10.
Default
Disabled
Command Mode
Interface configuration
Usage Guidelines
After DECnet routing has been enabled, you must assign a cost to each interface over which you want DECnet to run. Assigning a cost in effect enables DECnet routing for an interface. Most DECnet installations have an individualized routing strategy for using costs. Therefore, check the routing strategy used at your installation to ensure that costs you specify are consistent with those set for other hosts on the network.
Example
The following example establishes a DECnet routing process for the router and sets the router's DECnet address to 21.456, then sets a cost of 4 for the Ethernet 0 interface:
To provide DECnet encapsulation over Token Ring, use the decnet encapsulation interface configuration command.
decnet encapsulation {pre-dec | dec}
Syntax Description
pre-dec
Configures routers for operation on the same Token Ring with routers running software versions prior to 9.1. In this mode, Cisco routers cannot communicate with non-Cisco equipment. Referred to as Cisco-style encapsulation.
dec
Provides encapsulation that is compatible with other Digital equipment. All Cisco routers must be running Software Release 9.1 or later.
Default
Encapsulation is compatible with other Digital equipment.
Command Mode
Interface configuration
Usage Guidelines
If you have both Software Release 9.0 and 9.1 routers in the same network, you must use the pre-dec encapsulation type on the 9.1 routers.
Note You must first enable DECnet routing on the selected Token Ring interface before you can
configure the DECnet encapsulation mode.
Example
The following example sets Cisco-style encapsulation for DECnet routing, which means that Cisco and Digital equipment will not interoperate over Token Ring:
To change the interval for sending broadcast hello messages, use the decnet hello-timerinterface configuration command. To restore the default value, use the no form of this command.
decnet hello-timer seconds no decnet hello-timer
Syntax Description
seconds
Interval at which the router sends hello messages. It can be a decimal number in the range 1 through 8191 seconds; the default is 15 seconds.
Default
15 seconds
Command Mode
Interface configuration
Usage Guidelines
The router broadcasts hello messages on all interfaces with DECnet enabled. Other hosts on the network use the hello messages to identify the hosts with which they can communicate directly. On extremely slow serial lines, you may want to increase the default value to reduce overhead on the line.
Example
The following example increases the hello interval to 2 minutes (120 seconds) on interface serial 1:
Use the decnet host global configuration command to associate a name-to-DECnet address mapping, which will show up in the output of various commands. To disable name mapping, use the no form of this command.
decnet host name decnet-address no decnet host name
Syntax Description
name
A name you choose that uniquely identifies this DECnet address.
decnet-address
Source address. DECnet addresses are written in the form area.node. For example, 50.4 is node 4 in area 50. All addresses are in decimal.
Default
No name is defined.
Command Mode
Global configuration
Usage Guidelines
The assigned name is displayed, where applicable, in show decnet routeand show hosts EXEC command output.
The name can also be used with the ping decnet command.
Example
The following example defines name-to-DECnet address mapping:
decnet host cisco1 3.33
router# show decnet route
Area Cost Hops Next Hop to Node Expires Prio
*2 0 0 (Local) -> 2.33
*3 4 1 Ethernet1 -> CISCO1 33 64 A+
router# show hosts
Default domain is cisco.com
Name/address lookup uses domain service
Name servers are 255.255.255.255
Host Flags Age Type Address(es)
CISCO1 (perm, OK) 0 DECnet 3.33
decnet in-routing-filter
To provide access control to hello messages or routing information received on an interface, use the decnet in-routing-filter interface configuration command. Use the no form of this command to remove access control.
decnet in-routing-filter access-list-number no decnet in-routing-filter
Syntax Description
access-list-number
Standard DECnet access list. This list applies to source addresses. The value can be in the range 300 through 399.
Default
No access control is defined.
Command Mode
Interface configuration
Example
In the following example, interface Ethernet 0 is set up with a DECnet in-routing filter of 321, which means that any hello messages sent from addresses that are denied in list 321 will be ignored. Additionally, all node addresses listed in received routing messages on this interface will be checked against the access list, and only routes passing the filter will be considered usable.
DECnet network number you map to; DECnet numbers range from 0 through 3.
real-address
Numeric DECnet address (10.5, for example).
Syntax Description
Default
No address translation is defined.
Command Mode
Global configuration
Usage Guidelines
Keep the following limitations in mind when configuring the Address Translation Gateway (ATG):
Both nodes that want to communicate across the ATG must exist in the translation map. Other nodes outside of the map will see route advertisements for the mapped address but will be unable to communicate with them. An unmapped node trying to communicate with a mapped node will always get the message "Node unreachable." This can be confusing if another nearby node can communicate with mapped nodes because it is also a mapped node.
Third-party DECnet applications could fail if they pass node number information in a data stream (most likely a sign of a poorly designed application).
Routing information for mapped addresses is static and does not reflect the reachability of the actual node in the destination network.
As an additional feature and security caution, DECnet "Poor Man's Routing" can be used between nodes outside of the translation map as long as those nodes have access to nodes that are in the map, so that a user on node B could issue the following VMS command:
$ dir A::D::E::
When a Poor Man's Routing connection is made between two networks, only the two adjacent nodes between the networks will have any direct knowledge about the other network. Application-level network access may then be specified to route through the connection.
Note We do not support Poor Man's Routing directly; the intermediate nodes must be VMS
systems with Poor Man's Routing enabled in file access language (FAL).
Example
In the following example, packets in Network 0 sent to address 19.5 will be routed to Network 1, and the destination address will be translated to 50.1. Packets sent to address 47.1 in Network 1 will be routed to Network 0 as 19.1.
To configure the router with a maximum number of node addresses, use the decnet max-address global configuration command.
decnet [network-number] max-address value
Syntax Description
network-number
(Optional) Network number in the range 0 through 3. Specified when using Address Translation Gateway (ATG). If not specified, the default is network 0.
value
A number less than or equal to 1023 that represents the maximum address possible on the network. In general, all routers on the network should use the same value for this argument. The default is 1023.
Default
1023 node addresses
Command Mode
Global configuration
Usage Guidelines
DECnet routers do not have the concept of aging out a route. Therefore, all possible areas or nodes must be advertised as unreachable if they cannot be reached. Since it is best to keep routing updates small, you need to indicate the default maximum possible node and area numbers that can exist in the network.
Example
The following example configures a small network to a maximum address value of 300:
To set the largest number of areas that the router can handle in its routing table, use the decnet max-area global configuration command.
decnet [network-number] max-area area-number
Syntax Description
network-number
(Optional) Network number in the range 0 through 3. Specified when using Address Translation Gateway (ATG). If not specified, the default is network 0.
area-number
Area number from 1 through 63. Like the decnet max-addressglobal configuration command value, this argument controls the sizes of internal routing tables and of messages sent to other nodes.All routers on the network should use the same maximum address value. The default is 63.
Default
63 areas
Command Mode
Global configuration
Example
In the following example, the largest area to be stored in the routing table is 45:
To set the maximum cost specification for intra-area routing, use the decnet max-cost global configuration command.
decnet [network-number] max-cost cost
Syntax
network-number
(Optional) Network number in the range 0 through 3. Specified when using Address Translation Gateway (ATG). If not specified, the default is network 0.
cost
Cost from 1 through 1022. The default is 1022.
Description
Default
1022
Command Mode
Global configuration
Usage Guidelines
The router ignores routes within its local area that have a cost greater than the value you specify.
Example
In the following example, the node type is specified as a Level 1 router and the maximum cost is set to 335. Any route whose cost exceeds 335 will be considered unreachable by this router.
To set the maximum hop count specification value for intra-area routing, use the decnet max-hops global configuration command.
decnet [network-number] max-hops hop-count
Syntax
network-number
(Optional) Network number in the range 0 through 3. Specified when using Address Translation Gateway (ATG). If not specified, the default is network 0.
hop-count
Hop count from 1 through 30. The router ignores routes that have a hop count greater than the corresponding value of this parameter. The default is 30 hops.
Description
Default
30 hops
Command Mode
Global configuration
Example
The following example sets the router to be a Level 1 router, then sets a maximum hop count of 2:
To define the maximum number of equal-cost paths to a destination that the router will keep in its routing table, use the decnet max-paths global configuration command.
decnet [network-number] max-paths value
Syntax Description
network-number
(Optional) Network number in the range 0 through 3. Specified when using Address Translation Gateway (ATG). If not specified, the default is network 0.
value
Decimal number equal to the maximum number of equal-cost paths the router will save. The valid range is from 1 through 31. The default is 1.
Default
1 equal-cost path
Command Mode
Global configuration
Usage Guidelines
Limiting the number of equal-cost paths can save memory on routers with limited memory or very large configurations. Additionally, in networks with a large number of multiple paths and end-systems with limited ability to cache out-of-sequence packets, performance may suffer when traffic is split between many paths.
Limiting the size of the routing table will not affect your router's ability to recover from network failures transparently, provided that you do not make the maximum number of paths too small. If more than the specified number of equal-cost paths exist, and one of those paths suddenly becomes unusable, the router will discover an additional path from the paths it has been ignoring.
Example
In the following example, the router will save no more than three equal-cost paths:
To set the limit on the number of times a packet can pass through a router, use the decnet max-visits global configuration command.
decnet [network-number] max-visits value
network-number
(Optional) Network number in the range 0 through 3. Specified when using Address Translation Gateway (ATG). If not specified, the default is network 0.
value
Number of times a packet can pass through a router. It can be a decimal number in the range 1 through 63. If a packet exceeds value, the router discards the packet. Digital recommends that the value of the max-visits parameter be at least twice that of the max-hops parameter, to allow packets to still reach their destinations when routes are changing. The default is 63 times.
Syntax Description
Default
63 times
Command Mode
Global configuration
Example
The following example of intra-area routing configuration specifies Level 1 routing, a maximum hop count of 28, and maximum number of visits of 62 (which is more than twice 28).
Use the decnet multicast-map interface configuration command to specify a mapping between DECnet multicast addresses and Token Ring functional addresses, other than the default mapping. The no form of this command deletes the specified information.
decnet multicast-map multicast-address-type functional-address no decnet multicast-map multicast-address-type functional-address
multicast-address-type
Type of multicast address that is used. The following are valid values for the argument:
iv-all-routers(All Phase-IV routers)
iv-all-endnodes (All Phase-IV endnodes)
iv-prime-all-routers (All Phase IV Prime routers)
functional-address
Functional MAC address that this multicast ID will map to. In the form of "c000.xxxx.yyyy."
Syntax Description
Default
Enabled, with the default mapping listed in Table 16-2.
Command Mode
Interface configuration
Usage Guidelines
This command is valid for Token Ring interfaces only. The command will reject a functional address that does not start with "C000" or "c000."
Routing multicasts and end node multicasts must be on different functional addresses.
Table 16-2 Default Mapping of DECnet Multicast Address Types and Token Ring Functional Addresses
DECnet Multicast Address Type
Token Ring Functional Address
L1 router L2 router
C000.1000.0000
End node
C000.0800.0000
DECnet Phase IV-Prime router
C000.1000.0000
Example
In the following example, interface Token Ring 1 is configured for multicasts of all Phase IV end nodes and the multicast ID is configured to map to MAC address c000.2222.3333.
(Optional) Network number in the range 0 through 3. Specified when using Address Translation Gateway (ATG). If not specified, the default is network 0.
area
Router participates in the DECnet routing protocol with other area routers, as described in the Digital documentation, and routes packets from and to routers in other areas. This is sometimes referred to as Level 2, or interarea, routing. An area router does not just handle interarea routing; it also acts as an intra-area or Level 1 router in its own area.
routing-iv
Router acts as an intra-area (standard DECnet Phase IV, Level 1 router) and ignores Level 2 routing packets. In this mode, it routes packets destined for other areas to a designated interarea router, exchanging packets with other end-nodes and routers in the same area.
Default
No node type is specified.
Command Mode
Global configuration
Example
In the following example, the router node type is specified as area, or Level 2:
To provide access control to routing information being sent out on an interface, use the decnet out-routing-filter interface configuration command. Use the no form of this command to remove access control.
decnet out-routing-filter access-list-number no decnet out-routing-filter
Syntax Description
access-list-number
Standard DECnet access list applying to source addresses. The value can be in the range 300 through 399.
Default
No access control to routing information is defined.
Command Mode
Interface configuration
Usage Guidelines
Addresses that fail this test are shown in the update message as unreachable.
Example
In the following example, interface Ethernet 1 is set up with a DECnet out-routing filter of 351. This filter is applied to addresses in the transmitted routing updates. Transmitted hello messages are not filtered.
To specify how the router will split the routable packets between equal-cost paths, use the decnet path-split-mode global configuration command with the appropriate keyword.
decnet path-split-mode {normal| interim}
Syntax Description
normal
Normal mode, where equal-cost paths are selected on a round-robin basis. This is the default.
interim
Traffic for any particular (higher-layer) session is always routed over the same path. This mode supports older implementations of DECnet (VMS Versions 4.5 and earlier) that do not support out-of-order packet caching. Other sessions may take another path, thus using equal-cost paths that a router may have for a particular destination.
Default
Normal mode
Command Mode
Global configuration
Example
In the following example, the router will split routable packets between equal-cost paths using the round-robin (or first-come, first-served) basis:
Use this form of the decnet propagate static global configuration command to enable static route propagation. The no form of this command disables propagation.
decnet route propagate static no decnet route propagate static
Syntax Description
This command has no arguments or keywords.
Default
No default routes are propagated.
Command Mode
Global configuration
Usage Guidelines
By default, DECnet static routes will not be propagated to other routers. Use the decnet propagate static command to enable static route propagation. A default route will be used only after DECnet conversion is checked.
Examples
The following example shows how to enable static route propagation for the specified static and default routes:
To enable fast-switching, use the decnet route-cache interface configuration command. To disable fast switching, use the no form of this command.
decnet route-cache no decnet route-cache
Syntax Description
This command has no arguments or keywords.
Default
Enabled
Command Mode
Interface configuration
Usage Guidelines
By default, our DECnet routing software implements fast switching of DECnet datagrams. There are times when it makes sense to disable fast switching. This is especially important when using rates slower than T1.
Fast switching uses memory space on interface cards. In situations where a high-bandwidth interface is writing large amounts of information to a low-bandwidth interface, additional memory could help avoid congestion on the slow interface.
Example
In the following example, fast switching is disabled on interface ethernet 0:
interface ethernet 0
no decnet route-cache
decnet router-priority
To elect a designated router to which packets will be sent when no destination is specified, use the decnet router-priority interface configuration command.
decnet router-priority value
Syntax
value
Priority of the router. This can be a number in the range 0 through 127. The larger the number the higher the priority. The default priority is 64.
Description
Default
64
Command Mode
Interface configuration
Usage Guidelines
The designated router is the router to which all end nodes on an Ethernet communicate if they do not know where else to send a packet. The designated router is chosen through an election process in which the router with the highest priority gets the job. When two or more routers on a single Ethernet in a single area share the same highest priority, the unit with the highest node number is elected. You can reset a router's priority to help ensure that it is elected designated router in its area.
On a LAN with both DECnet IV and DECnet IV Prime hosts, make sure that a bilingual router always becomes the designated router.
DECnet end systems use the designated router only when they have no other information about how to reach a particular system. The end systems maintain a cache of how to reach other systems on the network. The cache contains the following information:
<remote system DECnet address> <next hop DECnet address>
When an end system receives a packet, it examines three pieces of information: the intra-LAN bit, the source address, and the previous hop. If the intra-LAN bit is set, indicating that the packet has never left this wire (and thus the remote system is reachable without a router), a cache entry is created as follows:
<remote system DECnet address> = <source address>
<next hop DECnet address> = <source address>
If the intra-LAN bit is not set, indicating that the packet has come from another network, the cache entry is created as follows:
<remote system DECnet address> = <source address>
<next hop DECnet address> = <previous hop>
If there is no cache entry, then the designated router is used. This means that when starting a session, the designated router is used, but the reverse traffic will populate a cache entry so that the router can later communicate directly.
A DECnet IV Prime end node sends a packet to the Unknown Destination multicast if it has no cache entry for the destination and has no designated router.
Example
In the following example, DECnet priority for this router is set to 110 on Ethernet 1:
interface ethernet 1
decnet router-priority 110
decnet route (interface static route)
Use this form of the decnet routeglobal configuration command to create an interface static route. The no form of this command removes this route.
decnet route decnet-addressnext-hop-type number [snpa-address][hops [cost]] no decnet route decnet-addressnext-hop-type number
Syntax Description
decnet-address
DECnet address. This value is entered into a static routing table and used to match a destination DECnet address. Use a node address value of 0 to specify an area static route.
next-hop-type
Interface type.
number
Interface unit number.
snpa-address
(Optional) Optional for serial links; required for multiaccess networks.
hops
(Optional) Hop count to be associated with the route being advertised. Default is 0.
cost
(Optional) Cost to be associated with the route being advertised. Default is 0.
Default
No interface static routes are created.
Command Mode
Global configuration
Usage Guidelines
If you do not specify an SNPA address when you have a multiaccess network, you will receive an error message indicating a bad SNPA. By default, DECnet static routes will not be propagated to other routers. Use the decnet propagate static command to enable propagation.
Examples
The following example shows how to create a static route for a serial interface. No SNPA need be specified for point-to-point interfaces.
decnet route 3.1 serial 1
The following example shows how to create a static route for an Ethernet interface. The SNPA must be specified for an interface that is not point-to-point.
Use this form of the decnet route global configuration command to enter a specific static route. DECnet addresses that match are forwarded to the next-hop-address. The no form of this command removes this route.
decnet route decnet-addressnext-hop-address [hops [cost]] no decnet route decnet-addressnext-hop-address
Syntax Description
decnet-address
DECnet address. This value is entered into a static routing table and used to match a destination DECnet address. Use a node address value of 0 to specify an area static route.
next-hop-address
This value is used to establish the next hop of the route for forwarding packets.
hops
(Optional) Hop count to be associated with the route being advertised. Default is 0.
cost
(Optional) Cost to be associated with the route being advertised. Default is 0.
Default
No interface static routes are created.
Command Mode
Global configuration
Usage Guidelines
Area static routes can be configured by specifying a DECnet node address of 0. By default, DECnet static routes will not be propagated to other routers. Use the decnet propagate static command to enable propagation.
Examples
The following example shows how to create a static route for 1.1 that points to 1.9 and uses default values of 0 for the hops and cost:
decnet route 1.1 1.9
The following example shows how to create a static route for 3.100 that points to 3.4 and specifies values for the hops and cost:
decnet route 3.100 3.4 9 8
The following example shows how to create a static route for area 1 that points to 2.999:
Use this form of thedecnet routedefault global configuration command to create an interface default route. The no form of this command removes this route.
decnet route default next-hop-type number [snpa-address][[hops [cost]] no decnet route default next-hop-type number
Syntax Description
next-hop-type
Interface type.
number
Interface unit number.
snpa-address
(Optional) Optional for serial links; required for multiaccess networks.
hops
(Optional) Hop count to be associated with the route being advertised. Default is 0.
cost
(Optional) Cost to be associated with the route being advertised. Default is 0.
Default
No interface default routes are created.
Command Mode
Global configuration
Usage Guidelines
If you do not specify an SNPA address when you have a multiaccess network, you will receive an error message indicating a bad SNPA.
A default route will be used only after DECnet conversion is checked. DECnet default routes will not be propagated to other routers.
Examples
The following example shows how to create a default route for a serial interface. No SNPA need be specified for point-to-point interfaces.
decnet route default serial 1
The following example shows how to create a default route for an Ethernet interface. The SNPA must be specified for an interface that is not point-to-point.
Use this form of thedecnet route default global configuration command to enter a specific default route. The no form of this command removes this route.
This value is used to establish the next hop of the route for forwarding packets.
hops
(Optional) Hop count to be associated with the route being advertised. Default is 0.
cost
(Optional) Cost to be associated with the route being advertised. Default is 0.
Default
No interface default routes are created.
Command Mode
Global configuration
Usage Guidelines
A default route will be used only after DECnet conversion is checked. By default, DECnet static routes will not be propagated to other routers. Use the decnet propagate static command to enable propagation.
DECnet packets not for the current area are forwarded to the next-hop-address.
Examples
The following example shows how to create a default route for 1.3 which uses default values of 0 for hops and cost:
To enable DECnet routing, use the decnet routing global configuration command. To disable DECnet routing, use the no form of this command.
decnet [network-number] routing [iv-prime]decnet-address no decnet routing
Syntax Description
network-number
(Optional) Network number in the range 0 through 3. Specified when using Address Translation Gateway (ATG). If not specified, the default is network 0.
iv-prime
(Optional) Enables DECnet Phase IV Prime routing.
decnet-address
Address in DECnet format X.Y, where X is the area number and Y is the node number.
Default
Disabled
Command Mode
Global configuration
Usage Guidelines
Enabling DECnet changes the MAC addresses of the router's interfaces. This is not a problem on routers equipped with nonvolatile memory. On systems that attempt to get their IP network addresses from network servers rather than from nonvolatile memory, there may be a problem as with the hardware addresses changing and confusing other IP-speaking hosts. This potential problem can be avoided by configuring and enabling DECnet before enabling other protocols.
Note You can configure up to four DECnet networks (numbered 0 through 3). To set up multiple
DECnet networks, use the decnet global configuration commands with the appropriate network
number and keywords. If the network number is omitted from the commands, network 0 will be
configured for DECnet routing.
DECnet Phase IV Prime eliminates the DEC addressing restrictions so that DECnet nodes can coexist with systems running other protocols that have other MAC address restrictions. If iv-prime is not specified, only Phase IV will be enabled; configuring the MAC address will then make DECnet inoperable. The standard "AA-00-04-00" form will be set as the address of the interface on which DECnet is enabled. If Phase IV Prime was already running and this command is reissued without the iv-prime keyword (that is, going from Phase IV Prime to Phase IV), the command will return an error if any of the interfaces that have DECnet enabled have MAC addresses that are not compliant with DECnet Phase IV, requiring the user to evaluate conflicting interface commands.
The no form of this command will disable Phase IV and Phase IV Prime routing.
Example
In the following example, DECnet routing is enabled for the router in area 21 with node number 456:
To specify how often the router sends routing updates that list the hosts that the router can reach, use the decnet routing-timer interface configuration command. Use the no form of this command to disable the routing update timer.
decnet routing-timer seconds no decnet routing-timer
Syntax Description
seconds
Time, in seconds, from 1 through 65535. The default is 40 seconds.
Default
40 seconds
Command Mode
Interface configuration
Usage Guidelines
Other routers use this information to construct local routing tables. In a network where changes occur infrequently or do not need to be responded to immediately (it is small and uncomplicated, applications are not particularly sensitive to delays or occasional packet loss, slow serial links, and so on), increasing the time between routing updates reduces the amount of unnecessary network traffic. Digital calls this argument the broadcast routing timer because they use a different timer for serial lines; our DECnet implementation does not make this distinction.
Example
In the following example, a serial interface is set to broadcast routing updates every 2 minutes (120 seconds):
interface serial 0
decnet routing-timer 120
lat host-delay
To set the delayed acknowledgment for incoming LAT slave connections, use the lat host-delay global configurationcommand. To restore the default, use the no form of this command.
lat host-delay number no host-delay
Syntax Description
number
The delay in milliseconds.
Default
Disabled
Command Mode
Global configuration
Example
The following example sets the acknowledgment for incoming LAT slave connections to 100 milliseconds:
lat host-delay 100
lat service autocommand
To associate a command with a service, use the lat serviceautocommand global configuration command. To remove the specified autocommand, use the no form of this command.
lat service service-name autocommand command no lat service service-name autocommand command
Syntax Description
service-name
Name of the service.
command
Command to be associated with the service.
Default
No commands are automatically associated with a service.
Command Mode
Global configuration
Usage Guidelines
When an inbound connection is received for the specified service, the command associated with the service is automatically executed instead of the user receiving a virtual terminal session.
Authentication is bypassed for these services; only the LAT password is checked.
Note Do not use this option with the rotary keyword.
Example
The following example associates the command telnet readings to the service readings:
lat service readings autocommand telnet readings
ping (privileged)
Use the DECnet ping privileged EXEC command to send DECnet echo packets to test the reachability of a remote host over a DECnet network.
ping
Syntax Description
This command has no arguments or keywords.
Command Mode
Privileged EXEC
Usage Guidelines
To abort a ping session, type the escape sequence (by default, Ctrl-^ X, which is done by simultaneously pressing the Ctrl, Shift, and 6 keys, letting go, then pressing the X key).
Table 16-3 describes the test characters that the ping facility sends.
Table 16-3 Ping Test Characters
Character
Description
!
Each exclamation point indicates receipt of a reply.
.
Each period indicates the network server timed out while waiting for a reply.
U
A destination unreachable error PDU was received.
C
A congestion-experienced packet was received.
I
User interrupted test.
?
Unknown packet type.
&
Packet lifetime exceeded.
Sample DECnet Display Using a DECnet Address
The following display shows a sample DECnet ping session that uses a DECnet address to specify the source:
Router# ping
Protocol [ip]: decnet
Target DECnet address:2.16
Repeat count [5]:
Datagram size [100]:
Timeout in seconds [2]:
Type escape sequence to abort.
Sending 5, 100-byte DECnet Echos to 2.16, timeout is 2 seconds:
!!!!!
Success rate is 100 percent, round-trip min/avg/max = 1/4/8 ms
Table 16-4describes the fields shown in the display.
Table 16-4 Ping Field Descriptions
Field
Description
Protocol [ip]:
Default is IP.
Target DECnet address:
Prompts for the DECnet address of the destination node you plan to ping.
Repeat count [5]:
Number of ping packets that will be sent to the destination address. Default: 5.
Datagram size [100]:
Size of the ping packet (in bytes). Default: 100 bytes.
Timeout in seconds [2]:
Timeout interval (in seconds). Default: 2 seconds.
Use the DECnet ping user EXEC command to send DECnet echo packets to test the reachability of a remote host over a DECnet network.
ping decnet{host | address}
Syntax Description
decnet
DECnet protocol keyword.
host
DECnet host of system to ping.
address
DECnet address of system to ping.
Command Mode
EXEC
Usage Guidelines
The ping Exec command provides a basic user ping facility for DECnet users who do not have system privileges. This feature allows the router to perform the simple default ping functionality for the DECnet protocol. Only the nonverbose form of the ping command is supported for user-level pings.
To abort a ping session, type the escape sequence (by default, Ctrl-^ X, which is done by simultaneously pressing the Ctrl, Shift, and 6 keys, letting go, then pressing the X key).
Table 16-5 describes the test characters that the ping facility sends.
Table 16-5 Ping Test Characters
Character
Description
!
Each exclamation point indicates receipt of a reply.
.
Each period indicates the network server timed out while waiting for a reply.
U
A destination unreachable error PDU was received.
C
A congestion-experienced packet was received.
I
User interrupted test.
?
Unknown packet type.
&
Packet lifetime exceeded.
Sample DECnet Display Using a DECnet Address
The following display shows sample ping output when you ping the DECnet address of 2.16:
router> ping decnet 2.16
Sending 5, 100-byte DECnet Echos to 2.16, timeout is 2 seconds:
!!!!!
Success rate is 100 percent, round-trip min/avg/max = 1/4/8 ms
Use the show decnet privileged EXEC command to display the global DECnet parameters.
show decnet
Syntax Description
This command has no arguments or keywords.
Command Mode
Privileged EXEC
Sample Display
The following is sample output from the show decnet command:
Router# show decnet
Global DECnet parameters for network 0:
Local address is 19.15, node type is area (Phase-IV Prime)
Level-2 `Attached' flag is FALSE, nearest level-2 router is 19.5
Maximum node is 350, maximum area is 63, maximum visits is 63
Maximum paths is 1, path split mode is normal
Local maximum cost is 1022, maximum hops is 30
Area maximum cost is 1022, maximum hops is 30
Static routes *NOT* being sent in routing updates
Default route configured; next hop address of 2.100
Table 16-6 describes significant fields shown in the display.
Table 16-6 Show DECnet Field Descriptions
Field
Description
Global DECnet parameters for network 0:
Indicates the DECnet network number of the network being described.
Local address is 19.15
DECnet address of the router.
node type is area
Indicates the DECnet node type with which the interface has been configured. Possible values include area (area router) or routing-iv (intra-area router).
Level-2 `Attached' flag is FALSE
(DECnet Level-2 routers only) Indicates that this Level-2 router is not "attached" (does not have reachability to other DECnet Phase IV areas). If the `Attached' flag is TRUE, the router has reachability to other areas.
If the `Attached' flag is FALSE, other displays on this line are the following:
Nearest Level-2 router is NONE—(DECnet Level-1 routers only) Indicates that this Level-1 router has not heard from any eligible Level-2 router (to send out-of-area packets to)
Nearest Level-2 router is 1.200—(DECnet Level-1 routers only) Indicates that this router's nearest Level-2 router is 1.200. Any packets received by this router destined for other areas will be sent to 1.200.
(Phase-IV Prime)
Indicates that the router is running DECnet Phase IV Prime routing.
Maximum node is 350
Highest node number that the router will recognize.
maximum area is 63
Indicates the maximum DECnet area number, which is used to control the size of internal routing tables and messages sent to other routers. Range: 1 through 63. Default: 63.
maximum visits is 63
Indicates the maximum number of times (visits) a packet can pass through a router. Range: 1 through 63. Default: 63.
Maximum paths is 1
Indicates the maximum number of equal-cost paths the router will save. Range: 1 through 31. Default: 1.
path split mode is normal
Indicates how the router will split the routable packets among equal-cost paths. Possible values: normal (default) or interim.
Local maximum cost is 1022
For intra-area routes. Router ignores routes in its area that have a cost greater than this value.
maximum hops is 30
Indicates the maximum number of hops for a usable route within the local area. The router ignores routes within the local area that use more than this number of hops.
Area maximum cost is 1022
Indicates the maximum cost specification for interarea routing. The router ignores routes to other areas that have a cost greater than this value. Range: 1 through 1022: Default: 1022.
maximum hops is 30
Indicates the maximum number of hops for a usable route to other areas. The router ignores routes to other areas that use more than this number of hops.
Static routes *NOT* being sent in routing updates
Indicates static routes are not included in routing updates.
Default route configured; next hop address of 2.100
Indicates a default route is configured on this router and shows the next hop address.
show decnet interface
Use the show decnet interface EXEC command to display the global DECnet status and configuration for all interfaces, or the status and configuration for a specified interface.
show decnet interface [type number]
Syntax Description
type
(Optional) Interface type.
number
(Optional) Interface unit number.
Command Mode
EXEC
Sample Display
The following is sample output from the show decnet interface command when you do not specify an interface:
Router# show decnet interface e1
Global DECnet parameters for network 0:
Local address is 19.15, node type is area
Maximum node is 350, maximum area is 63, maximum visits is 63
Maximum paths is 1, path split mode is normal
Local maximum cost is 1022, maximum hops is 30
Area maximum cost is 1022, maximum hops is 30
Ethernet 1 is up, line protocol is up, encapsulation is ARPA
Interface cost is 4, priority is 64, DECnet network: 0
The designated router is 1.9
Sending HELLOs every 15 seconds, routing updates 40 seconds
Smallest router blocksize seen is 1498 bytes
Routing input list is not set, output list is not set
Access list is not set
DECnet fast switching is enabled
Number of L1 router adjacencies is : 3
Number of non-PhaseIV+ router adjacencies is : 3
Number of PhaseIV+ router adjacencies is : 0
Router is bilingual
Table 16-7 describes significant fields shown in the display.
Table 16-7 Show DECnet Interface Field Descriptions when an Interface Is Not Specified
Field
Description
Global DECnet parameters for network 0:
Indicates the DECnet network number of the network being described.
Local address is 19.15
DECnet address of the router.
node type is area
Indicates the DECnet node type with which the interface has been configured. Possible values include area (area router) or routing-iv (intra-area router).
Maximum node is 350
Highest node number that the router will recognize.
maximum area is 63
Indicates the maximum DECnet area number, which is used to control the size of internal routing tables and messages sent to other routers. Range: 1 through 63. Default: 63.
maximum visits is 63
Indicates the maximum number of times (visits) a packet can pass through a router. Range: 1 through 63. Default: 63.
Maximum paths is 1
Indicates the maximum number of equal-cost paths the router will save. Range: 1 through 31. Default: 1.
path split mode is normal
Indicates how the router will split the routable packets among equal-cost paths. Possible values: normal (default) or interim.
Local maximum cost is 1022
For intra-area routes. Router ignores routes in its area that have a cost greater than this value.
maximum hops is 30
Indicates the maximum number of hops for a usable route within the local area. The router ignores routes within the local area that use more than this number of hops.
Area maximum cost is 1022
Indicates the maximum cost specification for interarea routing. The router ignores routes to other areas that have a cost greater than this value. Range: 1 through 1022: Default: 1022.
maximum hops is 30
Indicates the maximum number of hops for a usable route to other areas. The router ignores routes to other areas that use more than this number of hops.
Ethernet 0 is up
Indicates whether the interface hardware is currently active and if it has been taken down by an administrator.
line protocol is up
Indicates whether the software processes that handle the line protocol believe the interface is usable (that is, whether keepalives are successful).
encapsulation is ARPA
Indicates the encapsulation type.
Interface cost is 4
Indicates the cost that has been assigned to this interface using thedecnet cost interface configuration command. If there are multiple paths to a destination, the one with the lowest cost is selected.
priority is 64
Indicates the priority that has been assigned to this router on this interface. End systems will select the router with the highest priority as their designated router.
DECnet network: 0
Indicates that this interface is on DECnet network 0. This fact is significant only if Address Translation Gateway (ATG) is turned on.
The designated router is 1.3
Indicates the designated router on this particular LAN.
Sending HELLOs every 15 seconds
Indicates the frequency of hello packets.
routing updates 40 seconds
Indicates the frequency of routing updates.
Smallest router blocksize seen is 1498 bytes
Indicates the largest size of packets being sent on all routers on the LAN.
Routing input list is not set, output list is not set
Indicates that no access restrictions on incoming (or outgoing) router update or hello messages have been set for this interface.
Access list is not set
Indicates that no access lists have been configured for the interface.
DECnet fast switching is enabled
Indicates that fast switching is enabled.
Number of L1 router adjacencies is : 1
Indicates how many Level 1 adjacencies the router has on this interface.
Number of non-PhaseIV+ router adjacencies is : 3
Number of L1 and L2 routers on this interface that are not running Phase IV+.
Number of PhaseIV+ router adjacencies is : 0
Number of L2 routers on this interface that are running Phase IV+.
Router is bilingual
The router's MAC address on this interface is Phase IV-compatible (that is, it takes the form AA-00-04-00-xx-yy or 55-00-20-00-aa-bb on interfaces where the address is bit swapped). This means that the router will behave as both a Phase IV and a Phase IV Prime router.
Sample Display
The following is sample output from the show decnet interface command when you specify an interface:
Router# show decnet interface e 0
Ethernet0 is up, line protocol is up, encapsulation is ARPA
Interface cost is 4, priority is 64, DECnet network: 0
The designated router is 1.3
Sending HELLOs every 15 seconds, routing updates 40 seconds
Smallest router blocksize seen is 1498 bytes
Routing input list is not set, output list is not set
Access list is not set
DECnet fast switching is enabled
Number of L1 router adjacencies is : 1
Number of non-PhaseIV+ router adjacencies is : 3
Number of PhaseIV+ router adjacencies is : 0
Router is bilingual
Table 16-8 describes significant fields shown in the display.
Table 16-8 Show DECnet Interface Field Descriptions when an Interface Is Specified
Field
Description
Ethernet 0 is up
Indicates whether the interface hardware is currently active and if it has been taken down by an administrator.
line protocol is up
Indicates whether the software processes that handle the line protocol believe the interface is usable (that is, whether keepalives are successful).
encapsulation is ARPA
Indicates the encapsulation type.
Interface cost is 4
Indicates the cost that has been assigned to this interface using thedecnet cost interface configuration command. If there are multiple paths to a destination, the one with the lowest cost is selected.
priority is 64
Indicates the priority that has been assigned to this router on this interface. End systems will select the router with the highest priority as their designated router.
DECnet network: 0
Indicates that this interface is on DECnet network 0. This fact is significant only if Address Translation Gateway (ATG) is turned on.
The designated router is 1.3
Indicates the designated router on this particular LAN.
Sending HELLOs every 15 seconds
Indicates the frequency of hello packets.
routing updates 40 seconds
Indicates the frequency of routing updates.
Smallest router blocksize seen is 1498 bytes
Indicates the largest size of packets being sent on all routers on the LAN.
Routing input list is not set, output list is not set
Indicates that no access restrictions on incoming (or outgoing) router update or hello messages have been set for this interface.
Access list is not set
Indicates that no access lists have been configured for the interface.
DECnet fast switching is enabled
Indicates that fast switching is enabled.
Number of L1 router adjacencies is : 1
Indicates how many Level 1 adjacencies the router has on this interface.
Number of non-PhaseIV+ router adjacencies is : 3
Number of L1 and L2 routers on this interface that are not running Phase IV+.
Number of PhaseIV+ router adjacencies is : 0
Number of L2 routers on this interface that are running Phase IV+.
Router is bilingual
The router's MAC address on this interface is Phase IV-compatible (that is, it takes the form AA-00-04-00-xx-yy or 55-00-20-00-aa-bb on interfaces where the address is bit swapped). This means that the router will behave as both a Phase IV and a Phase IV Prime router.
show decnet map
Use the show decnet map EXEC command to display the address mapping information used by the DECnet Address Translation Gateway.
show decnet map
Syntax Description
This command has no arguments or keywords.
Command Mode
EXEC
Sample Display
The following is sample output from the show decnet map command:
Router# show decnet map
Net Node -> Net Node Uses Cost Hops
0 1.100 1 2.100 0
Table 16-9 describes significant fields shown in the display.
Table 16-9 Show DECnet Map Field Descriptions
Field
Description
Net Node - Net Node
Net number and node address.
Uses
Number of times this map was used.
Cost
Cost associated with route.
Hop
Number of hops to destination mode.
show decnet neighbors
Use the show decnet neighbors privileged EXEC command to display all Phase IV and Phase IV Prime adjacencies and the MAC address associated with each neighbor.
show decnet neighbors
Syntax Description
This command has no arguments or keywords.
Command Mode
Privileged EXEC
Sample Display
The following is sample output from the show decnet neighbors command:
Router# show decnet neighbors
Net Node Interface MAC address Flags
0 3.11 Ethernet0 aa00.0400.0b0c A
0 1.1 Ethernet0 aa00.0400.0104 V
0 1.3 Ethernet1 aa00.0400.0304 V
0 1.6 Ethernet1 aa00.0400.0604 V
0 2.2 TokenRing 5500.2000.4020 V IV-PRIME
Table 16-10 describes the fields shown in the display.
Table 16-10 Show DECnet Neighbors Field Descriptions
Field
Description
Net
Number of the DECnet network this adjacency is in.
Node
DECnet address of the adjacency.
Interface
Interface over which this adjacency was heard.
MAC address
MAC address that this adjacency is using on this interface.
Flags
A: L2 adjacency. V: L1 adjacency. IV-PRIME: DECnet Phase IV Prime adjacency.
show decnet route
Use the show decnet route EXEC command to display the DECnet routing table.
show decnet route [decnet-address]
Syntax Description
decnet-address
(Optional) DECnet address and, when specified, the first hop route to that address is displayed.
Command Mode
EXEC
Sample Display
The following is sample output from the show decnet route command when a DECnet address name was not specified, so the entire routing table is displayed:
Router# show decnet route
Area Cost Hops Next Hop to Node Expires Prio
1 4 1 Ethernet1 -> 1.300 26 64 A
*1 4 1 Ethernet1 -> 1.400 37 64 A
*2 8 2 Ethernet1 -> 1.400
*5 0 0 (Local) -> 5.5
*10 4 1 Ethernet2 -> 10.1 36 64 A
*13 11 3 Ethernet1 -> 1.400
*44 22 6 Ethernet1 -> 1.400
*51 18 4 Ethernet1 -> 1.400
*61 1 1 (OSI) -> 5.5
*62 1 1 (OSI) -> 5.5
*3 0 0 (STATIC) Ethernet0, snpa aa00.0400.0404
*4 0 0 (STATIC) Serial0
*6 5 4 (STATIC) forwarding to 2.3
Node Cost Hops Next Hop to Node Expires Prio
*(Area) 0 0 (Local) -> 5.5
*5.5 0 0 (Local) -> 5.5 32 64 A+
*DEFAULT* : 0 0 using next hop address of 2.100
Router#
As the display shows, the show decnet route command can display more than one route for a destination when equal-cost paths have been set with the decnet max-paths global configuration command, and when there is more than one equal-cost path to a destination. The display also shows that this node is an area router.
Table 16-11 describes significant fields shown in the display.
Table 16-11 Show DECnet Route Field Descriptions
Field
Description
*
Currently selected route for a particular destination. In interim mode, the selected route will never appear to change.
Node
DECnet address of this (reachable) destination.
(Area)
All Level 1 routes are displayed in this section except for this the first entry, which points to the nearest Level 2 router.
Cost
Assigned cost for the interface, based on a recommended value for the underlying media. Range: 1 through 63. No default.
Hops
Number of hops to this node from the router being monitored.
Next Hop to Node
DECnet address of the next hop a packet will take to get to the final destination as well as the interface.
(Local)
The address that the router is configured with.
(OSI)
Indicates that this entry was created by the decnet advertise command.
(STATIC)
Indicates that this entry was created by the decnet route command.
Expires
Displays how many seconds from now this entry expires.
Prio
Router priority of this node.
V
Adjacent Level 1 router.
A+
Adjacent Level 2 (area) router; A indicates that this is an adjacency created from a Phase IV hello, A+ indicates that thisis an adjacency created from a Phase IV+ hello.
show decnet static
Use the show decnetstatic privileged EXEC command to display all statically configured DECnet routes.
showdecnet static
Syntax Description
This command has no arguments or keywords.
Command Mode
Privileged EXEC
Usage Guidelines
All static rotues are stored in a static route queue, which allows static routes to be reinstated when DECnet routing is turned off then on again.
Not all routes in the static route queue will show up in the routing table. This will happen under the following conditions:
The router is a Level 1 router and any of the following apply. Assume the router DECnet address is 1.1:
A Level 2 area static route is configured.
decnet route 2.0 1.2
A static route is configured not in the same area as the router.
decnet route 3.10 1.200
A static route is configured for the same address as the router.
decnet route 1.1 1.200
The router is a Level 2 router and any of the following apply. Assume the router DECnet address is 2.1:
A Level 1 static router is not in the same area as the router.
decnet route 4.1 10.200
Note that the following route will appear because a Level 2 route is installed to area 4:
decnet route 4.0 10.200
A Level 2 static route is configured for the router's own area.
decnet route 2.0 10.200
A static route is configured for the same address as the router.
decnet route 2.1 5.4 s 1
Sample Display
The following is sample output from the show decnetstatic command:
Router# show decnet static
Address Cost Hops Next hop SNPA
3 0 0 Ethernet0 aa00.0400.0404
5 0 0 Serial0
5.100 0 0 Serial2
DEFAULT 0 0 2.100
6 5 4 2.3
Note that this router is a Level 2 router with DECnet address of 1.2, so a static route configured for 5.100 is not relevant here. This route appears in the show decnet static display, but not in the routing table.
show decnet traffic
The show decnet traffic EXEC command shows the DECnet traffic statistics, including datagrams sent, received, and forwarded.
show decnet traffic
Syntax Description
This command has no arguments or keywords.
Command Mode
EXEC
Sample Display
The following is sample output from the show decnet traffic command:
Router# show decnet traffic
Total: 42 received, 0 format errors, 0 unimplemented
0 not a gateway, 0 no memory, 0 no routing vector
0 non-empty queue encountered
Hellos: 21 received, 0 bad, 0 other area, 16 sent
Level 1 routing: 14 received, 0 bad, 0 other area, 16 sent
Level 2 routing: 7 received, 0 not primary router, 8 sent
Data: 0 received, 0 not long format, 0 too many visits
0 forwarded, 0 returned, 0 converted, 0 local destination
0 access control failed, 0 no route, 0 encapsulation failed
0 inactive network, 0 incomplete map
Table 16-12 describes the fields shown in the display.
Table 16-12 Show DECnet Traffic Field Descriptions
Field
Description
Total:
Displays the totals of packet types received.
received
Total of all types of DECnet packets received.
format errors
Lists the number of packets that appeared to be DECnet, but were formatted incorrectly. The number in the received field includes these packets.
0 unimplemented
Reports the number of incoming packets that are DECnet control packets, and how many specify a service that the router does not implement. This includes services implemented to forward Level 1 and Level 2 routing information, and router and end-system hello packets.
0 not a gateway
Reports the total number of packets received while not routing DECnet.
0 no memory
Records transaction attempts when the system has run out of memory.
0 no routing vector
Indicates that either a routing update came in from another router when the router did not have an adjacency for it, or it had no routing vector for the type of routing update. Use the debug decnet-routing EXEC command for more information.
0 non-empty queue encountered
Number of times the DECnet output process encountered a non-empty interface output queue.
HELLOs:
Displays the number of hello messages received and sent.
received
Displays the total number of hello messages received. All protocol types are included.
bad
Displays the total number of "bad" hello messages received. Invoke the EXEC command debug decnet to display more information about why the hello message was judged as bad.
other area
Displays the total number of hello messages received from nodes on other areas when the router is a Level 1 router only.
sent
Displays the total number of hello messages sent.
Level 1 routing:
Displays the Level 1 routing updates received and sent.
received
Displays the total number of Level 1 routing updates received.
bad
Displays the total number of Level 1 updates received that were judged to be bad.
other area
Displays the total number of Level 1 updates from nodes in other areas.
sent
Displays the total number of Level 1 updates sent.
Level 2 routing:
Displays the Level 2 routing updates received and sent.
received
Displays the total number of Level 2 updates received.
not primary router
Should always be zero.
sent
Displays the total number of Level 2 updates sent.
Data:
Displays the number of data packets received and sent.
received
Displays the total number of noncontrol (data) packets received.
not long format
Displays the number of packets received which are not in the long DECnet format. This number should always be zero. If it is not, investigate the source of the improperly formatted packets.
too many visits
Lists the number of packets received which have visited too many routers and have been flushed.
forwarded
Lists the total number of packets forwarded.
returned
Lists the total number of packets returned to the sender at the senders' request.
converted
Displays the number of Phase IV packets converted to Phase V packets.
local destination
Packets received that are destined for this router.
access control failed
Lists the packets dropped because access control required it.
no route
Lists the total packets dropped because the router did not know where to forward them.
encapsulation failed
Lists the number of packets that could not be encapsulated. This usually happens where there are entries missing in a map for a public data network, such as X.25 or Frame Relay. This can also occur if an interface is set for an encapsulation for which there is no defined DECnet encapsulation (such as PPP on serial interfaces).
inactive network
Displays the number of packets that appear to come from a known interface, or that ATG returned because they did not make sense.
incomplete map
Counts the number of packets that failed address translation. This usually means a node that is not in the ATG map is trying to access a node in another network advertised by the ATG.
