This chapter explains how to set up Cisco ONS 15454 SDHs in internet protocol (IP) networks. The chapter does not provide a comprehensive explanation of IP networking concepts and procedures.
Note To set up ONS 15454 SDHs within an IP network, you must work with a LAN administrator or other
individual at your site who has IP network training and experience. To learn more about IP
networking, many outside resources are available. IP Routing Fundamentals, by Mark Sportack
(Cisco Press, 1999), provides a comprehensive introduction to routing concepts and protocols in IP
networks.
Table 4-1 lists IP networking topics. Table 4-2 lists IP networking routing procedures on the ONS 15454 SDH.
Determine how your network will be connected. There are many different ONS 15454 SDH connection options within an IP environment:
ONS 15454 SDHs can be connected to LANs directly or through a router.
IP Subnetting can create ONS 15454 SDH node groups, allowing you to provision non-DCC connected nodes in a network.
Different IP functions and protocols can be used to achieve specific network goals. For example, Proxy Address Resolution Protocol (ARP) enables one LAN-connected ONS 15454 SDH to serve as a gateway for ONS 15454 SDHs that are not connected to the LAN.
You can create static routes to enable connections among multiple CTC sessions with ONS 15454 SDHs that reside on the same subnet but have different destination IP addresses.
If ONS 15454 SDHs are connected to OSPF networks, ONS 15454 SDH network information is automatically communicated across multiple LANs and WANs.
ONS 15454 SDH IP addressing generally has eight common scenarios or configurations. Use the scenarios as building blocks for more complex network configurations.
Table 4-3 provides a general list of items to check when setting up ONS 15454 SDHs in IP networks. Additional procedures for troubleshooting Ethernet connections and IP networks are provided in "Ethernet Operation."
Table 4-3 General ONS 15454 SDH IP Networking Checklist
Item
What to check
PC/workstation
Each CTC computer must have the following:
Web browser, Java Runtime Environment, Java.policy file: A java.policy file modified for CTC must be installed
ONS 15454 SDHs (backplane wire-wrap pins or RJ-45 port) and network hub/switch
Router ports and hub/switch ports
ONS 15454 SDH hub/switch ports
Set the hub or switch port that is connected to the ONS 15454 SDH to 10 Mbps half-duplex.
Ping
Ping the node to test connections between computers and ONS 15454 SDHs.
IP addresses/subnet masks
ONS 15454 SDH IP addresses and subnet masks are set up correctly.
Optical connectivity
ONS 15454 SDH optical trunk ports are in service; DCC is enabled on each trunk port
4.2 Scenario 1: CTC and ONS 15454 SDHs on Same Subnet
Scenario 1 shows a basic ONS 15454 SDH LAN configuration (Figure 4-1). The ONS 15454 SDHs and CTC computer reside on the same subnet. All ONS 15454 SDHs connect to LAN A, and all ONS 15454 SDHs have DCC connections.
Note Instructions for creating DCC connections are provided in
"SDH Topologies" within the
MS-SPRing, SNCP, and linear ADM procedures.
Figure 4-1 Scenario 1: CTC and ONS 15454 SDHs on same subnet
4.3 Scenario 2: CTC and ONS 15454 SDHs Connected to Router
In Scenario 2 the CTC computer resides on a subnet (192.168.1.0) and attaches to LAN A (Figure 4-2). The ONS 15454 SDHs reside on a different subnet (192.168.2.0) and attach to LAN B. A router connects LAN A to LAN B. The IP address of router interface A is set to LAN A (192.168.1.1), and the IP address of router interface B is set to LAN B (192.168.2.1).
On the CTC computer, the default gateway is set to router interface A. If the LAN uses DHCP (Dynamic Host Configuration Protocol), the default gateway and IP address are assigned automatically. In the Figure 4-2 example, a DHCP server is not available.
Figure 4-2 Scenario 2: CTC and ONS 15454 SDHs connected to router
4.4 Scenario 3: Using Proxy ARP to Enable an ONS 15454 SDH Gateway
Scenario 3 is similar to Scenario 1, but only one ONS 15454 SDH (node #1) connects to the LAN (Figure 4-3). Two ONS 15454 SDHs (#2 and #3) connect to ONS 15454 SDH #1 through the SDH DCC. Because all three ONS 15454 SDHs are on the same subnet, Proxy ARP enables ONS 15454 SDH #1 to serve as a gateway for ONS 15454 SDHs #2 and #3.
Figure 4-3 Scenario 3: Using Proxy ARP
ARP matches higher-level IP addresses to the physical addresses of the destination host. It uses a lookup table (called ARP cache) to perform the translation. When the address is not found in the ARP cache, a broadcast is sent out on the network with a special format called the ARP request. If one of the machines on the network recognizes its own IP address in the request, it sends an ARP reply back to the requesting host. The reply contains the physical hardware address of the receiving host. The requesting host stores this address in its ARP cache so that all subsequent datagrams (packets) to this destination IP address can be translated to a physical address.
Proxy ARP enables one LAN-connected ONS 15454 SDH to respond to the ARP request for ONS 15454 SDHs not connected to the LAN. (ONS 15454 SDH Proxy ARP requires no user configuration.) For this to occur, the DCC-connected ONS 15454 SDHs must reside on the same subnet. When a LAN device sends an ARP request to an ONS 15454 SDH that is not connected to the LAN, the gateway ONS 15454 SDH returns its MAC address to the LAN device. The LAN device then sends the datagram for the remote ONS 15454 SDH to the MAC address of the proxy ONS 15454 SDH. The proxy ONS 15454 SDH uses its routing table to forward the datagram to the non-LAN ONS 15454 SDH. The routing table is built using the OSPF IP routing protocol. (An OSPF example is presented in the "Scenario 7: Using OSPF" section.)
4.5 Scenario 4: Default Gateway on CTC Computer
Scenario 4 is similar to Scenario 3, but nodes #2 and #3 reside on different subnets, 192.168.2.0 and 192.168.3.0, respectively (Figure 4-4). Node #1 and the CTC computer are on subnet 192.168.1.0. The network includes different subnets because Proxy ARP is not used. In order for the CTC computer to communicate with ONS 15454 SDHs #2 and #3, ONS 15454 SDH #1 is entered as the default gateway on the CTC computer using the "Setting Up the CTC Computer" section.
Figure 4-4 Scenario 4: Default gateway on a CTC computer
4.6 Scenario 5: Using Static Routes to Connect to LANs
Static routes are used for two purposes:
To connect ONS 15454 SDHs to CTC sessions on one subnet connected by a router to ONS 15454 SDHs residing on another subnet. (These static routes are not needed if OSPF is enabled. Scenario 7 shows an OSPF example.)
To enable multiple CTC sessions among ONS 15454 SDHs residing on the same subnet. (Scenario 6 shows an example.)
In Figure 4-5, one CTC residing on subnet 192.168.1.0 connects to a router through interface A. (The router is not set up with OSPF.) ONS 15454 SDHs residing on subnet 192.168.2.0 are connected through ONS 15454 SDH #1 to the router through interface B. Proxy ARP enables ONS 15454 SDH #1 as a gateway for ONS 15454 SDHs #2 and #3. To connect to CTC computers on LAN A, a static route is created on ONS 15454 SDH #1.
Figure 4-5 Scenario 5: Static route with one CTC computer used as a destination
The destination and subnet mask entries control access to the ONS 15454 SDHs:
If a single CTC computer is connected to router, enter the complete CTC "host route" IP address as the destination with a subnet mask of 255.255.255.255.
If CTC computers on a subnet are connected to router, enter the destination subnet (in this example, 192.168.1.0) and a subnet mask of 255.255.255.0.
If all CTC computers are connected to router, enter a destination of 0.0.0.0 and a subnet mask of 0.0.0.0. Figure 4-6 shows an example.
The IP address of router interface B is entered as the next hop, and the cost (number of hops from source to destination) is 2.
Figure 4-6 Scenario 5: Static route with multiple LAN destinations
Procedure: Create a Static Route
Purpose
Use this procedure to create a static route. Static routes are used for two purposes:
To connect ONS 15454 SDHs to CTC sessions on one subnet connected by a router to ONS 15454 SDHs residing on another subnet.
To enable multiple CTC sessions among ONS 15454 SDHs residing on the same subnet.
Onsite/Remote
Onsite or remote
Step 1 Start CTC for an ONS 15454 SDH node and choose the Provisioning > Network tabs.
Step 2 Click the Static Routing tab. Click Create.
Figure 4-7 Create static route dialog box
Step 3 In the Create Static Route dialog box enter the following:
Destination—Enter the IP address of the computer running CTC. To limit access to one computer, enter the full IP address (in the example, 192.168.1.100). To allow access to all computers on the 192.168.1.0 subnet, enter 192.168.1.0 and a subnet mask of 255.255.255.0. You can enter a destination of 0.0.0.0 to allow access to all CTC computers that connect to the router.
Mask—Enter a subnet mask. If the destination is a host route (i.e., one CTC computer), enter a 32-bit subnet mask (255.255.255.255). If the destination is a subnet, adjust the subnet mask accordingly, for example, 255.255.255.0. If the destination is 0.0.0.0, enter a subnet mask of 0.0.0.0 to provide access to all CTC computers.
Next Hop—Enter the IP address of the router port (in this example, 192.168.90.1) or the node IP address if the CTC computer is connected to the node directly.
Cost—Enter the number of hops between the ONS 15454 SDH and the computer. In this example, the cost is two, one hop from the ONS 15454 SDH to the router and a second hop from the router to the CTC workstation.
Step 4 Click OK. Verify that the static route displays in the Static Route window, or ping the node.
4.7 Scenario 6: Static Route for Multiple CTCs
Scenario 6 shows a static route used when multiple CTC computers need to access ONS 15454 SDHs residing on the same subnet (Figure 4-8). In this scenario, CTC #1 and #2 and all ONS 15454 SDHs are on the same IP subnet; ONS 15454 SDH #1 and CTC #1 are attached to LAN A. ONS 15454 SDH #2 and CTC #2 are attached to LAN B. Static routes are added to ONS 15454 SDH #1 pointing to CTC #1, and to ONS 15454 SDH #2 pointing to CTC #2. The static route is entered from the node's perspective.
Figure 4-8 Scenario 6: Static route for multiple CTCs
4.8 Scenario 7: Using OSPF
Open Shortest Path First (OSPF) is a link state Internet routing protocol. Link state protocols use a "hello protocol" to monitor their links with adjacent routers and to test the status of their links to their neighbors. Link state protocols advertise their directly-connected networks and their active links. Each link state router captures the link state "advertisements" and puts them together to create a topology of the entire network or area. From this database, the router calculates a routing table by constructing a shortest path tree. Routes are continuously recalculated to capture ongoing topology changes.
ONS 15454 SDHs use the OSPF protocol in internal ONS 15454 SDH networks for node discovery, circuit routing, and node management. You can enable OSPF on the ONS 15454 SDHs so that the ONS 15454 SDH topology is sent to OSPF routers on a LAN. Advertising the ONS 15454 SDH network topology to LAN routers eliminates the need to manually enter static routes for ONS 15454 SDH subnetworks. Figure 4-9 shows the same network enabled for OSPF. Figure 4-10 shows the same network without OSPF. Static routes must be manually added to the router in order for CTC computers on LAN A to communicate with ONS 15454 SDH #2 and #3 because these nodes reside on different subnets.
OSPF divides networks into smaller regions, called areas. An area is a collection of networked end systems, routers, and transmission facilities organized by traffic patterns. Each OSPF area has a unique ID number, known as the area ID, that can range from 0 to 4,294,967,295. Every OSPF network has one backbone area called "area 0." All other OSPF areas must connect to area 0.
When you enable ONS 15454 SDH OSPF topology for advertising to an OSPF network, you must assign an OSPF area ID to the ONS 15454 SDH network. Coordinate the area ID number assignment with your LAN administrator. In general, all DCC-connected ONS 15454 SDHs are assigned the same OSPF area ID.
Figure 4-9 Scenario 7: OSPF enabled
Figure 4-10 Scenario 7: OSPF not enabled
Procedure: Set up OSPF
Purpose
Use the following procedure to enable OSPF on each ONS 15454 SDH node that you want included in the OSPF network topology.
Prerequisite procedures
ONS 15454 SDH OSPF settings must match the router OSPF settings, so you will need to get the OSPF Area ID, Hello and Dead intervals, and authentication key (if OSPF authentication is enabled) from the router to which the ONS 15454 SDH network is connected before enabling OSPF.
Onsite/Remote
Onsite or remote
Step 1 Start CTC for an ONS 15454 SDH node.
Step 2 In node view, choose the Provisioning > Network > OSPF tabs. The OSPF pane has several options (Figure 4-11).
Figure 4-11 Enabling OSPF on the ONS 15454 SDH
Step 3 On the top left side, complete the following:
DCC OSPF Area ID—Enter the number that identifies the ONS 15454 SDHs as a unique OSPF area. The OSPF area number can be an integer between 0 and 4294967295, and it can take a form similar to an IP address. The number must be unique to the LAN OSPF area.
DCC Metric—This value is normally unchanged. It sets a "cost" for sending packets across the DCC, which is used by OSPF routers to calculate the shortest path. This value should always be higher than the LAN metric. The default DCC metric is 100.
Step 4 In the OSPF on LAN area, complete the following:
OSPF active on LAN—When checked, enables ONS 15454 SDH OSPF topology to be advertised to OSPF routers on the LAN. Enable this field on ONS 15454 SDHs that directly connect to OSPF routers.
Area ID for LAN Port—Enter the OSPF area ID for the router port where the ONS 15454 SDH is connected. (This number is different from the DCC Area ID.)
Step 5 In the Authentication area, complete the following:
Type—If the router where the ONS 15454 SDH is connected uses authentication, choose Simple Password. Otherwise, choose No Authentication.
Key—If authentication is enabled, enter the OSPF key (password).
Step 6 In the Priority and Intervals area, complete the following:
The OSPF priority and intervals default to values most commonly used by OSPF routers. In the Priority and Invervals area, verify that these values match those used by the OSPF router where the ONS 15454 SDH is connected.
Router Priority—Used to select the designated router for a subnet.
Hello Interval (sec)—Sets the number of seconds between OSPF "hello" packet advertisements sent by OSPF routers. Ten seconds is the default.
Dead Interval—Sets the number of seconds that will pass while an OSPF router's packets are not visible before its neighbors declare the router down. Forty seconds is the default.
Transit Delay (sec)—Indicates the service speed. One second is the default.
Retransmit Interval (sec)—Sets the time that will elapse before a packet is resent. Five seconds is the default.
LAN Metric—Sets a "cost" for sending packets across the LAN. This value should always be lower than the DCC metric. Ten is the default.
Figure 4-12 The OSPF area range table and virtual link table
Step 7 In the OSPF Area Range Table area, complete the following:
Area range tables consolidate the information that is propagated outside an OSPF Area border. One ONS 15454 SDH in the ONS 15454 SDH OSPF area is connected to the OSPF router. An area range table on this node points the router to the other nodes that reside within the ONS 15454 SDH OSPF area.
To create an area range table:
a. Under OSPF Area Range Table, click Create.
b. In the Create Area Range dialog box, enter the following:
Range Address—Enter the area IP address for the ONS 15454 SDHs that reside within the OSPF area. For example, if the ONS 15454 SDH OSPF area includes nodes with IP addresses 10.10.20.100, 10.10.30.150, 10.10.40.200, and 10.10.50.250, the range address would be 10.10.0.0.
Range Area ID—Enter the OSPF area ID for the ONS 15454 SDHs. This is either the ID in the DCC OSPF Area ID field or the ID in the Area ID for LAN Port field.
Mask Length—Enter the subnet mask length. In the Range Address example, this is 16.
Mask—Displays the subnet mask used to reach the destination host or network.
Advertise—Check if you want to advertise the OSPF range table.
c. Click OK.
Step 8 All OSPF areas must be connected to Area 0. If the ONS 15454 SDH OSPF area is not physically connected to Area 0, use the following steps to create a virtual link table that will provide the disconnected area with a logical path to Area 0:
a. Under OSPF Virtual Link Table, click Create.
b. In the Create Virtual Link dialog box, complete the following fields (OSPF settings must match OSPF settings for the ONS 15454 SDH OSPF area):
Neighbor—Enter the router ID of the Area 0 router.
Transit Delay (sec)—The service speed. One second is the default.
Retransmit Int (sec)—Sets the time that will elapse before a packet is resent. Five seconds is the default.
Hello Int (sec)—The number of seconds between OSPF "hello" packet advertisements sent by OSPF routers. Ten seconds is the default.
Dead Int (sec)—Sets the number of seconds that will pass while an OSPF router's packets are not visible before its neighbors declare the router down. Forty seconds is the default.
Auth Type—If the router where the ONS 15454 SDH is connected uses authentication, choose Simple Password. Otherwise, set it to No Authentication.
c. Click OK.
Step 9 After entering ONS 15454 SDH OSPF area data, click Apply.
If you changed the Area ID, the TCC-I cards will reset, one at a time.
4.9 Scenario 8: Provisioning the ONS 15454 SDH Proxy Server
The ONS 15454 proxy server is a set of functions that allows you to network ONS 15454 SDHs in environments where visibility and accessibility between ONS 15454s and CTC computers must be restricted. For example, you can set up a network so that field technicians and network operating center (NOC) personnel can both access the same ONS 15454 SDHs while preventing the field technicians from accessing and the NOC LAN. To do this, one ONS 15454 SDH is provisioned as a gateway NE (GNE) and the other ONS 15454 SDHs are provisioned as element NEs (ENEs). The GNE ONS 15454 SDH tunnels connections between CTC computers and ENE ONS 15454 SDHs, providing management capability while preventing access for non-ONS 15454 SDH management purposes.
The ONS 15454 SDH proxy server performs the following tasks:
Isolates DCC IP traffic from Ethernet (craft port) traffic and accept packets based on filtering rules. The filtering rules (see Table 4-5 and Table 4-6) depend on whether the packet arrives at the ONS 15454 SDH DCC or TCC-I Ethernet interface.
Monitors ARP request packets on its Ethernet port. If the ARP request is from an address that is not on the current subnet, the ONS 15454 SDH creates an entry its ARP table. The ARP entry allows the ONS 15454 SDH to reply to an address over the local Ethernet so craft technicians can connect to ONS 15454 SDHs without changing the IP addresses of their computers.
Processes SNTP/NTP requests. Element ONS 15454 SDH NEs can derive timing from an SNTP/NTP LAN server through the GNE ONS 15454 SDH.
Process SNMPv1 traps. The GNE ONS 15454 SDH receives SNMPv1 traps from the ENE ONS 15454 SDHs and forwards them to all provisioned SNMPv1 trap destinations.
The ONS 15454 SDH proxy server is provisioned using three checkboxes on the Provisioning > Network > General tab (see Figure 4-13):
Craft Access Only—When this option is enabled, the ONS 15454 SDH neither installs nor advertises default or static routes. CTC computers can communicate with the ONS 15454 SDH, but they cannot communicate directly with any other DCC-connected ONS 15454 SDH.
Enable Proxy—When this option is enabled, the ONS 15454 SDH serves as a proxy for connections between CTC clients and ONS 15454 SDHs that are DCC-connected to the proxy ONS 15454 SDH. The CTC client establishes connections to DCC-connected nodes through the proxy node. The CTC client can connect to nodes that it cannot directly reach from the host on which it runs. If Enable Proxy is off, the node does not proxy for any CTC clients, although any established proxy connections will continue until the CTC client exits.
Enable Firewall—If this option is selected, the node prevents IP traffic from being routed between the DCC and the LAN port. The ONS 15454 SDH can communicate with machines connected to the LAN port or connected through the DCC. However, the DCC-connected machines cannot communicate with the LAN-connected machines, and the LAN-connected machines cannot communicate with the DCC-connected machines. A CTC client using the LAN to connect to the firewall-enabled node can use the proxy capability to manage the DCC-connected nodes that would otherwise be unreachable. A CTC client connected to a DCC-connected node can only manage other DCC-connected nodes and the firewall itself.
Figure 4-13 Proxy Server Gateway Settings
Figure 4-14 shows an ONS 15454 SDH proxy server implementation. A GNE ONS 15454 SDH is connected to a central office LAN and to ENE ONS 15454 SDHs. The central office LAN is connected to a NOC LAN, which has CTC computers. The NOC CTC computer and craft technicians must both be able to access the ONS 15454 SDH ENEs. However, the craft technicians must be prevented from accessing or seeing the NOC or central office LANs.
In the example, the ONS 15454 SDH GNE is assigned an IP address within the central office LAN and is physically connected to the LAN through its LAN port. ONS 15454 SDH ENEs are assigned IP addresses that are outside the central office LAN and given private network IP addresses. If the ONS 15454 SDH ENEs are co-located, the craft LAN ports could be connected to a hub. However, the hub should have no other network connections.
Figure 4-14 ONS 15454 SDH Proxy Server with GNE and ENEs on the same subnet
Table 4-4 shows recommended settings for ONS 15454 SDH GNEs and ENEs in the configuration shown in Figure 4-14.
Table 4-4 ONS 15454 SDH Gateway and Element NE Settings
Setting
ONS 15454 SDH Gateway NE
ONS 15454 SDH Element NE
Craft Access Only
Off
On
Enable Proxy
On
On
Enable Firewall
On
On
OSPF
Off
Off
SNTP Server (if used)
SNTP server IP address
Set to ONS 15454 SDH GNE IP address
SNMP (if used)
SNMPv1 trap destinations
Set SNMPv1 trap destinations to ONS 15454 SDH GNE
Figure 4-15 shows the same proxy server implementation with ONS 15454 SDH ENEs on different subnets. Figure 4-16 shows the implementation with ONS 15454 SDH ENEs in multiple rings. In each example, ONS 15454 SDH GNEs and ENEs are provisioned with the settings shown in Table 4-4.
Figure 4-15 Scenario 8: ONS 15454 SDH Proxy Server with GNE and ENEs on different subnets
Figure 4-16 Scenario 8: ONS 15454 SDH Proxy Server with ENEs on multiple rings
Table 4-5 shows the rules the ONS 15454 SDH follows to filter packets when Enable Firewall is enabled. If the packet is addressed to the ONS 15454 SDH, additional rules, shown in Table 4-6, are applied. Rejected packets are silently discarded.
Table 4-5 Proxy Server Firewall Filtering Rules
Packets Arrive At
Accepted
TCC-I Ethernet Interface
The ONS 15454 SDH itself
The ONS 15454 SDH's subnet broadcast address
Within the 224.0.0.0/8 network (reserved network used for standard multicast messages)
255.255.255.255
DCC Interface
The ONS 15454 SDH itself
An OSPF peer (another DCC-connected ONS 15454 SDH)
Within the 224.0.0.0/8 network
Table 4-6 Proxy Server Firewall Filtering Rules When Packet Addressed to ONS 15454 SDH
Packets Arrive At
Accepted
Rejected
TCC-I Ethernet Interface
All UDP packets except those in the Rejected column
UDP packets addressed to the SNMP trap relay port (391) are rejected
DCC Interface
All UDP packets
All TCP packets except those in the Rejected column
OSPF packets
ICMP packets
TCP packets addressed to the telnet port are rejected.
TCP packets addressed to the IO card telnet ports are rejected.
TCP packets addressed to the proxy server port are rejected.
All other packets
If you implement the proxy server, keep the following rules in mind:
1. All DCC-connected ONS 15454 SDHs on the same Ethernet segment must have the same Craft Access Only setting. Mixed values will produce unpredictable results, and may leave some nodes unreachable through the shared Ethernet segment.
2. All DCC-connected ONS 15454 SDHs on the same Ethernet segment must have the same Enable Firewall setting. Mixed values will produce unpredictable results. Some nodes may become unreachable.
3. All DCC-connected ONS 15454 SDHs in the same SDCC area must have the same Enable Firewall setting. Mixed values will produce unpredictable results. Some nodes may become unreachable.
4. If you enable Enable Firewall, always enable Enable Proxy. If Enable Proxy is not enabled, CTC will not be able to see nodes on the DCC side of the ONS 15454 SDH.
5. If Craft Access Only is enabled, enable Enable Proxy. If Enable Proxy is not enabled, CTC will not be able to see nodes on the DCC side of the ONS 15454 SDH.
If nodes become unreachable in cases 1 and 2, you can correct the setting by performing one of the following:
Disconnect the craft computer from the unreachable ONS 15454 SDH. Connect to the ONS 15454 SDH through another ONS 15454 SDH in the network that has a DCC connection to the unreachable ONS 15454 SDH.
Disconnect the Ethernet cable from the unreachable ONS 15454 SDH. Connect a CTC computer directly to the ONS 15454 SDH.
4.10 Viewing the ONS 15454 SDH Routing Table
ONS 15454 SDH routing information is displayed on the Maintenance > Routing Table tabs (Figure 4-17). The routing table provides the following information:
Destination—Displays the IP address of the destination network or host.
Mask—Displays the subnet mask used to reach the destination host or network.
Gateway—Displays the IP address of the gateway used to reach the destination network or host.
Usage—Shows the number of times this route has been used.
Interface—Shows the ONS 15454 SDH interface used to access the destination. Values are:
cpm0—the ONS 15454 SDH Ethernet interface, that is, the RJ-45 jack on the TCC-I and the LAN connectors on the MIC-C/T/P FMEC.
pdcc0—an SDCC interface, that is, an STM-N trunk card identified as the SDCC termination.
lo0—a loopback interface
Figure 4-17 Viewing the ONS 15454 SDH routing table
Table 4-7 shows sample routing entries for an ONS 15454 SDH.
Table 4-7 Sample Routing Table Entries
Entry
Destination
Mask
Gateway
Interface
1
0.0.0.0
0.0.0.0
172.20.214.1
cpm0
2
172.20.214.0
255.255.255.0
172.20.214.92
cpm0
3
172.20.214.92
255.255.255.255
127.0.0.1
lo0
4
172.20.214.93
255.255.255.255
0.0.0.0
pdcc0
5
172.20.214.94
255.255.255.255
172.20.214.93
pdcc0
Entry #1 shows the following:
Destination (0.0.0.0) is the default route entry. All undefined destination network or host entries on this routing table will be mapped to the default route entry.
Mask (0.0.0.0) is always 0 for the default route.
Gateway (172.20.214.1) is the default gateway address. All outbound traffic that cannot be found in this routing table or is not on the node's local subnet will be sent to this gateway.
Interface (cpm0) indicates that the ONS 15454 SDH Ethernet interface is used to reach the gateway.
Entry #2 shows the following:
Destination (172.20.214.0) is the destination network IP address.
Mask (255.255.255.0) is a 24-bit mask, meaning all addresses within the 172.20.214.0 subnet can be a destination.
Gateway (172.20.214.92) is the gateway address. All outbound traffic belonging to this network is sent to this gateway.
Interface (cpm0) indicates that the ONS 15454 SDH Ethernet interface is used to reach the gateway.
Entry #3 shows the following:
Destination (172.20.214.92) is the destination host IP address.
Mask (255.255.255.255) is a 32 bit mask, meaning only the 172.20.214.92 address is a destination.
Gateway (127.0.0.1) is a loopback address. The host directs network traffic to itself using this address.
Interface (lo0) indicates that the local loopback interface is used to reach the gateway.
Entry #4 shows the following:
Destination (172.20.214.93) is the destination host IP address.
Mask (255.255.255.255) is a 32 bit mask, meaning only the 172.20.214.93 address is a destination.
Gateway (0.0.0.0) means the destination host is directly attached to the node.
Interface (pdcc0) indicates that an SDH SDCC interface is used to reach the destination host.
Entry #5 shows a DCC-connected node that is accessible through a node that is not directly connected:
Destination (172.20.214.94) is the destination host IP address.
Mask (255.255.255.255) is a 32-bit mask, meaning only the 172.20.214.94 address is a destination.
Gateway (172.20.214.93) indicates that the destination host is accessed through a node with IP address 172.20.214.93.
Interface (pdcc0) indicates that an SDH SDCC interface is used to reach the gateway.
