|
|
This appendix describes the Web Cache Communication Protocol (WCCP) Version 2 feature. (WCCP is also known as Web Cache Control Protocol and Web Cache Coordination Protocol.) This appendix includes information on the benefits of this feature, and other information you may need to work with WCCP Version 2. This appendix includes the following sections:
Cisco developed the Web Cache Communication Protocol (WCCP) within Cisco IOS software to enable routers or switches to transparently redirect packets to network caches. It does not interfere with normal router or switch operations. Using WCCP, the router redirects requests on configured TCP ports to network caches rather than to intended host sites. It also balances traffic load across a cache cluster and ensures fault-tolerant and fail-safe operation. As Content Engines are added to or deleted from a cache cluster, the WCCP-aware router or switch dynamically adjusts its redirection map to reflect the currently available caches, resulting in maximized performance and content availability.
WCCP Version 2 contains the following features:
WCCP Version 2 enables a series of Content Engines, called a Content Engine cluster, to connect to multiple routers. This feature provides redundancy and a more distributed architecture for instances when a Content Engine needs to connect to a large number of interfaces. This strategy also has the benefit of keeping all the Content Engines in a single cluster, avoiding unnecessary duplication of web pages across several clusters.
With WCCP Version 1, only a single router services a cluster, becoming the default home router for the cluster. In this scenario, this router is the device that performs all the IP packet redirection. Figure B-1 illustrates how this configuration appears.
The following sequence of events details how this process works:
1. Each Content Engine records the IP address of the router servicing the cluster.
2. The Content Engines then transmit their IP addresses to the router, indicating their presence to one another in the cluster.
3. The router then replies to the Content Engines, establishing that each can connect to others in the cluster, and providing a view (a list) of Content Engine addresses in the cluster, indicating that all can recognize one another.
4. Once the view has been established, one Content Engine is designated the lead and indicates to the router how IP packet redirection should be performed. The lead Content Engine is defined as one seen by all the routers in the service group and that has the lowest IP address.
With WCCP Version 2, multiple routers can service a cluster. This allows any of the available routers in a service group to redirect packets to each of the Content Engines in the cluster. Figure B-2 illustrates how this configuration appears.
You can configure the router to run one of the following cache-related services:
The subset of Content Engines within a cluster and routers connected to the cluster that are running the same service is known as a service group.
Available services include TCP and User Datagram Protocol (UDP) redirection for streaming media applications.
Using WCCP Version 1, the Content Engines were configured with the address of the single router. WCCP Version 2 requires that each Content Engine be aware of all the routers in the service group. To specify the addresses of all the routers in a service group, you must choose one of the following methods:
The multicast option is easier to configure because you have to specify only a single address on each Content Engine. This option also allows you to add and remove routers from a service group dynamically, without having to reconfigure the Content Engines with a different list of addresses each time.
The following sequence of events details how WCCP Version 2 configuration works:
1. Each Content Engine is configured with a list of routers.
2. Each Content Engine announces its presence and a list of all routers with which it has established communications. The routers reply with their view (list) of Content Engines in the group.
3. Once the view is consistent across all Content Engines in the cluster, one Content Engine is designated the lead and sets the policy that the routers need to deploy in redirecting packets.
You must also perform these tasks to configure the routers that will become members of the service group:
For network configurations in which the Content Engine sends to a target router a packet that needs to traverse an intervening router, the router being traversed must be configured to perform IP multicast routing. You must configure two components to enable traversal over an intervening router:
Routers and Content Engines become aware of one another and form a service group using a management protocol. Once the service group has been established, one of the Content Engines is designated to determine load assignments among the Content Engines. The Content Engines also send periodic "Here I am" messages to the routers which allows them to rediscover the Content Engines.
If there is a group of Content Engines, the one seen by all routers and the one that has the lowest IP address becomes the lead Content Engine. The role of this Content Engine is to determine how traffic should be allocated across Content Engines. The assignment information is passed to the entire service group from the designated Content Engine so that the routers of the group can redirect the packets properly and the Content Engines of the group can manage their load better.
WCCP Version 2 provides authentication that enables you to control which routers and Content Engines become part of the service group. You use passwords and the HMAC MD5 standard set by the ip wccp [password [0-7] password] command to control service group membership.
Cisco Express Forwarding (CEF) has been integrated into WCCP Version 2 to achieve optimal performance during packet redirection.
WCCP Version 2 enables more TCP ports to have traffic redirected to the Content Engine. Previously, web-cached information could be redirected only if it was destined for TCP port 80. Many applications require packets intended for other ports to be redirected, for example, proxy web cache handling, FTP proxy caching, web caching for ports other than 80, and RealAudio, and video.
Packets that the Content Engines do not service are tunneled back to the same router from which they were received. When a router receives a formerly redirected packet, it knows not to redirect it again.
The criteria for determining whether to redirect the traffic are:
Note that service information has been added to the protocol to indicate which service the WCCP messages refer to. This information is used to help verify that service group members are all using or providing the same service.
WCCP Version 2 filters packets to determine which redirected packets have been returned from the Content Engine and which ones have not. It does not redirect the ones that have been returned, because the Content Engine has determined that the packets should not be processed. WCCP Version 2 returns packets that the Content Engine does not service to the same router from which they were transmitted. Typical reasons why a Content Engine would reject packets and initiate packet return are:
 |
Note The packets are redirected to the source of the connection between the router and the Content Engine. Depending on the IOS version used, this could be either the address of the outgoing interface or the router IP address. In the latter case, it is important that the Content Engine has the router IP address stored in the router list. |
WCCP Version 2 has the capability to adjust the load being offered to individual Content Engines to provide more effective use of the resources available and at the same time help to ensure high quality of service to the clients. It uses two techniques to perform this task:
The Content Engine accepts traffic and establishes the connection with the client, acting as if it were the original destination server. Once the connection is established, if the object being requested is not available on the Content Engine, the engine then establishes its own connection out to the original destination server.
The following limitations apply to WCCP Version 2:
|
Note A Content Engine and a WCCP-enabled router cannot be separated by a firewall. The firewall handles only packet traffic toward the origin web server and does not handle packet traffic sent to the client by the Content Engine on behalf of the server. |
Before you use WCCP Version 2, you must complete the following tasks:
You can configure a router to run the web cache, custom web cache, and reverse proxy services associated with WCCP Version 2. The services can be configured simultaneously. Perform the following tasks to configure a cluster with multiple routers.
| Command | Purpose | |
|---|---|---|
Step 1 | Router(config)# ip wccp {web-cache |
service-number} [group-address groupaddress]
[redirect-list access-list] [group-list
access-list] [password [0-7] password]
| Turns the WCCP feature on or off for the specified service. |
Step 2 | Router(config)# interface type number
| Specifies an interface to configure and enters interface configuration mode. |
Step 3 | Router(config-if)# ip wccp {web-cache |
service-number} redirect {out | in}
| Enables WCCP redirection on the specified interface. |
Step 4 | Router(config-if)# ip wccp redirect exclude in
| Allows inbound packets on this interface to be excluded from redirection. |
| Command | Purpose | |
|---|---|---|
Step 1 | Router(config)# ip wccp web-cache
| Turns on the protocol for web caching. |
Step 2 | Router(config)# interface type number
| Specifies an interface for web caching. |
Step 3 | Router(config-if)# ip wccp web-cache redirect out
| Enables the check on packets to determine whether they need to be redirected to a web cache. |
| Command | Purpose | |
|---|---|---|
Step 1 | Router(config)# ip wccp 99
| Turns the WCCP feature on or off for the reverse proxy service. The service number for reverse proxy is 99. |
Step 2 | Router(config)# interface type number
| Specifies an interface for the reverse proxy service. |
Step 3 | Router(config-if)# ip wccp 99 redirect out
| Specifies "out" for the reverse proxy service. |
| Command | Purpose | |
|---|---|---|
Step 1 | Router(config)# ip wccp 98
| Turns the WCCP feature on or off for the custom web cache service. The service number for custom web cache is 98. |
Step 2 | Router(config)# interface type number
| Specifies an interface on which the custom web cache service will run. |
Step 3 | Router(config-if)# ip wccp 98 redirect out
| Specifies "out" for the custom web cache service. |
| Command | Purpose | |
|---|---|---|
Step 1 | Router(config)# ip wccp 90
| Turns the WCCP feature on or off for the generic web cache service. The service numbers for generic web cache services are 90 to 97. |
Step 2 | Router(config)# interface type number
| Specifies an interface on which the reverse proxy service will run. |
Step 3 | Router(config-if)# ip wccp 90 redirect out
| Specifies "out" for the custom web cache service. |
| Command | Purpose | |
|---|---|---|
Step 1 | Router(config)# ip wccp web-cache group-address
groupipaddress
| Configures the group address for the service group. |
Step 2 | Router(config)# interface type number
| Specifies an interface that will listen for the multicast address. |
Step 3 | Router(config-if)# ip wccp web-cache group-listen
| Configures an interface on a router to enable or disable the reception of IP multicast packets for WCCP. |
| Command | Purpose | |
|---|---|---|
Step 1 | Router(config)# ip wccp web-cache group-list
access-list
| Indicates to the router which Content Engine IP addresses to allow packets from. |
Step 2 | Router(config)# access-list access-list number permit
host host-address
| Creates an access list that enables or disables traffic redirection to the Content Engine. |
| Command | Purpose | |
|---|---|---|
Step 1 | Router(config)# ip wccp web-cache password | Sets a password for the Content Engine that the router is trying to access. |
| Command | Purpose | |
|---|---|---|
Step 1 | Router(config)# ip wccp web-cache redirect-list
access-list number
| Sets the access list used to enable redirection. |
Step 2 | Router(config)# access-list access-list number deny
host host-address
| Creates an access list that enables or disables traffic redirection to the Content Engine. |
Step 3 | Router(config)# access-list access-list number permit
any any
| Sets the access list to enable access to any host. |
Step 1 To view the configuration, enter the show running-config command.
A sample configuration follows:
Console# show running-config
Building configuration...
Current configuration:
!
version 12.0
service timestamps debug uptime
service timestamps log uptime
no service password-encryption
service udp-small-servers
service tcp-small-servers
!
hostname router4
!
enable secret 5 $1$nSVy$faliJsVQXVPW.KuCxZNTh1
enable password alabama1
!
ip subnet-zero
ip wccp web-cache
ip wccp 99
ip domain-name cisco.com
ip name-server 10.1.1.1
ip name-server 10.1.1.2
ip name-server 10.1.1.3
!
!
!
interface Ethernet0
ip address 10.3.1.2 255.255.255.0
no ip directed-broadcast
ip wccp web-cache redirect out
ip wccp 99 redirect out
no ip route-cache
no ip mroute-cache
!
interface Ethernet1
ip address 10.4.1.1 255.255.255.0
no ip directed-broadcast
ip wccp 99 redirect out
no ip route-cache
no ip mroute-cache
!
interface Serial0
no ip address
no ip directed-broadcast
no ip route-cache
no ip mroute-cache
shutdown
!
interface Serial1
no ip address
no ip directed-broadcast
no ip route-cache
no ip mroute-cache
shutdown
!
ip default-gateway 10.3.1.1
ip classless
ip route 0.0.0.0 0.0.0.0 10.3.1.1
no ip http server
!
!
!
line con 0
transport input none
line aux 0
transport input all
line vty 0 4
password alaska1
login
!
end
Step 2 To view values associated with WCCP variables, enter the show ip wccp command. Output similar to the following is displayed:
Console# show ip wccp
Global WCCP Information:
Service Name: web-cache:
Number of Content Engines:1
Number of Routers:1
Total Packets Redirected:213
Redirect access-list:no_linux
Total Packets Denied Redirect:88
Total Packets Unassigned:-none-
Group access-list:0
Total Messages Denied to Group:0
Total Authentication failures:0
Service Name: 99
Number of Content Engines:1
Number of Routers:2
Total Packets Redirected:198
Redirect access-list:-none-
Total Packets Denied Redirect:0
Total Packets Unassigned:0
Group access-list:11
Total Messages Denied to Group:0
Total Authentication failures:0
| Command | Purpose |
|---|---|
Router# show ip wccp
or
Router# show ip wccp {web-cache | 90-99}
| Displays global statistics related to WCCP. |
Router# show ip wccp {web-cache | 90-99} detail
| Queries the router for information about which Content Engines the router has detected in a specific service group. The information can be displayed for service groups ranging in value from 90-99. |
Router# show ip interface
| Shows whether any ip wccp direct commands are configured on an interface. |
Router# show ip wccp {web-cache | 90-99} view
| Displays which devices in a particular service group have been detected and which Content Engines are not visible to all other routers to which the current router is connected. The information can be displayed for service groups ranging in value from 90-99. |
This section provides the following configuration examples:
The following example shows a general WCCP Version 2 configuration session:
|
Note You must enter the ip wccp version 2 command in all Version 2 configurations to enable redirection using WCCP Version 2. |
ip wccp web-cache group-address 224.1.1.100 password alabama1
interface ethernet0
ip wccp web-cache redirect out
The following example shows a web cache service configuration session:
configure terminal
ip wccp web-cache
interface ethernet 0
ip wccp web-cache redirect out
The following example shows a reverse proxy service configuration session:
configure terminal
ip wccp 99
interface ethernet 0
ip wccp 99 redirect out
The following example shows a custom web cache configuration session:
configure terminal
ip wccp 98
interface ethernet 0
ip wccp 98 redirect out
The following example shows a generic web cache configuration session:
configure terminal
ip wccp 91
interface ethernet 0
ip wccp 91 redirect out
The following example shows how to register a router to a multicast address of 192.168.0.0:
configure terminal
ip wccp web-cache group-address 172.168.0.0
interface ethernet 0
ip wccp web cache group-listen
To achieve better security, you can use a standard access list to notify the router which IP addresses are valid addresses for a Content Engine attempting to register with the current router. The following example shows a standard access list configuration session in which the access list number is 10 for some sample hosts:
configure terminal
access-list 10 permit host 10.1.1.1
access-list 10 permit host 10.1.1.2
access-list 10 permit host 10.1.1.3
ip wccp web-cache group-list 10
The following example shows a WCCP Version 2 password configuration session in which the password is alabama2:
configure terminal
ip wccp web-cache password alabama2
The router can be configured with access lists to permit or deny redirection of traffic to the Content Engine. In the following example, traffic conforming to the following criteria is not redirected by the router to the Content Engine:
router# configure terminal
router(config)# ip wccp web-cache redirect-list 120
router(config)# access-list 120 deny ip host 10.1.1.1 any
router(config)# access-list 120 deny ip any host 10.255.1.1
router(config)# access-list 120 permit ip any any
Traffic not explicitly permitted is implicitly denied redirection. The access-list 120 permit ip any any command explicitly permits all traffic (from any source en route to any destination) to be redirected to the Content Engine. Because criteria matching occurs in the order by which the commands are entered, the global permit command is the last command entered. For further information on access lists, refer to Cisco IOS software documentation.
The following example displays WCCP settings, using the show running-config command:
Console# show running-config
Building configuration...
Current configuration:
!
version 12.0
service timestamps debug uptime
service timestamps log uptime
no service password-encryption
service udp-small-servers
service tcp-small-servers
!
hostname router4
!
enable secret 5 $1$nSVy$faliJsVQXVPW.KuCxZNTh1
enable password alabama1
!
ip subnet-zero
ip wccp web-cache
ip wccp 99
ip domain-name cisco.com
ip name-server 10.1.1.1
ip name-server 10.1.1.2
ip name-server 10.1.1.3
!
!
!
interface Ethernet0
ip address 10.3.1.2 255.255.255.0
no ip directed-broadcast
ip wccp web-cache redirect out
ip wccp 99 redirect out
no ip route-cache
no ip mroute-cache
!
interface Ethernet1
ip address 10.4.1.1 255.255.255.0
no ip directed-broadcast
ip wccp 99 redirect out
no ip route-cache
no ip mroute-cache
!
interface Serial0
no ip address
no ip directed-broadcast
no ip route-cache
no ip mroute-cache
shutdown
!
interface Serial1
no ip address
no ip directed-broadcast
no ip route-cache
no ip mroute-cache
shutdown
!
ip default-gateway 10.3.1.1
ip classless
ip route 0.0.0.0 0.0.0.0 10.3.1.1
no ip http server
!
!
!
line con 0
transport input none
line aux 0
transport input all
line vty 0 4
password alaska1
login
!
end
This section documents new or modified commands that configure the WCCP Version 2 feature.
In Cisco IOS Release 12.0(1)T or a later version of Release 12.0 T, you can search and filter the output for show and more commands. This functionality is useful when you need to sort through large amounts of output, or if you want to exclude output that you do not need to see.
To use this functionality, enter a show or more command followed by the "pipe" character ( | ), one of the keywords begin, include, or exclude, and an expression that you want to search or filter on:
command | {begin | include | exclude} regular-expressionFollowing is an example of the show atm vc command in which you want the command output to begin with the first line where the expression "PeakRate" appears:
show atm vc | begin PeakRateFor more information on the search and filter functionality, refer to the Cisco IOS Release 12.0(1)T feature module titled CLI String Search.
To remove Web Cache Communication Protocol (WCCP) statistics maintained on the router either for a particular service or for all the services, use the clear ip wccp EXEC command.
clear ip wccp {web-cache | service-number}
Syntax Description
web-cache Directs the router to remove statistics for the web cache service. service-number Directs the router to remove statistics for a specified web cache service. The number can be from 0 to 99. The reverse proxy service is indicated by a value of 99.
Defaults
No default behavior or values
Command Modes
EXEC
Command History
11.1 CA This command was introduced. 11.2 P This command was introduced. 12.0(3)T This command has been expanded to be explicit about service.
Release
Modification
Usage Guidelines
Use the show ip wccp and show ip wccp detail commands to display WCCP statistics.
Examples
clear ip wccp web cache
Related Commands
ip wccp Directs a router to enable or disable the support for a service group. show ip wccp Displays global statistics related to the WCCP feature.
Command
Description
To direct a router to enable or disable the support for a Content Engine service group, use the ip wccp global configuration command. To remove the ability of a router to control support for a service group, use the no form of this command.
ip wccp {web-cache | service-number} [group-address groupaddress] [redirect-list access-list] [group-list access-list] [password [0-7] password]
Syntax Description
web-cache Enables the web cache service. service-number Identification number of the Web Cache Communication Protocol (WCCP) service being controlled by a router. The number can be from 0 to 99. The reverse proxy service is indicated by a value of 99. group-address (Optional) Directs the router to use a specified multicast IP address for communication with the WCCP service group. groupaddress (Optional) Multicast address used by the router to determine which Content Engine should receive redirected messages. redirect-list (Optional) Directs the router to use an access list to control traffic redirected to this service group. access-list (Optional) String (not to exceed 64 characters) that is the name of the access list that determines which traffic is redirected to a Content Engine. group-list (Optional) Directs the router to use an access list to determine which Content Engines are allowed to participate in the service group. access-list (Optional) String (not to exceed 64 characters) that is the name of the access list that determines which Content Engines are allowed to participate in the service group. password (Optional) String that directs the router to apply MD5 authentication to messages received from the service group specified by the service name given. Messages that are not accepted by the authentication are discarded. 0-7 (Optional) Value that indicates the HMAC MD5 algorithm used to encrypt the password. This value is generated when an encrypted password is created for the Content Engine. password (Optional) Password name that is combined with the HMAC MD5 value to create security for the connection between the router and the Content Engine.
Defaults
This command is disabled by default.
Command Modes
Global configuration
Command History
12.0(3)T This command was introduced.
Release
Modification
Examples
The following example shows a router configured to run WCCP reverse proxy service, using (listening to) the multicast address 172.31.0.0:
ip wccp 99 group-address 172.31.0.0
Related Commands
ip wccp group-listen Configures an interface on a router to enable or disable the reception of IP multicast packets for the WCCP feature.
Command
Description
To configure an interface on a router to enable or disable the reception of IP multicast packets for the Web Cache Communication Protocol (WCCP) feature, use the ip wccp group-listen interface configuration command. To remove control of the reception of IP multicast packets for the WCCP feature, use the no form of this command.
ip wccp {web-cache | service-number} group-listen
Syntax Description
web-cache Directs the router to transmit packets to the web cache service. service-number Identification number of the Content Engine service group being controlled by a router. The number can be from 0 to 99. The reverse proxy service is indicated by a value of 99.
Defaults
This command is disabled by default.
Command Modes
Interface configuration
Command History
12.0(3)T This command was introduced.
Release
Modification
Examples
The following example shows that multicast packets have been enabled for a web cache with an address of 192.168.0.0.
configure terminal
ip wccp web-cache group-address 192.168.0.0
interface ethernet 0
ip wccp web cache group-listen
Related Commands
ip wccp Directs a router to enable or disable the support for a service group. ip wccp redirect out Configures an interface to enable or disable the exclusion of a redirection check for packets that were received on the interface.
Command
Description
To configure an interface to enable or disable exclusion of packets received on an interface from being redirected to a Content Engine, use the ip wccp redirect exclude in interface configuration command. To disable a router's ability to verify that only appropriate packets are being redirected to a Content Engine, use the no form of this command.
ip wccp redirect exclude inSyntax Description
This command has no arguments or keywords.
Defaults
No default behavior or values
Command Modes
Interface configuration
Command History
12.0(3)T This command was introduced.
Release
Modification
Usage Guidelines
Note that the command is global to all the services and should be applied to any inbound interface that has been configured to be excluded from redirection on an outbound interface that the traffic will traverse.
Examples
configure terminal
ip wccp 99
interface ethernet0
ip wccp redirect exclude in
Related Commands
ip wccp Directs a router to enable or disable the support for a service group. ip wccp redirect out Configures an interface to enable or disable the exclusion of a redirection check for packets that were received on the interface.
Command
Description
To enable packet redirection on an outbound or inbound interface using Web Cache Communication Protocol (WCCP), use the ip wccp redirect interface configuration command. To disable WCCP redirection, use the no form of this command.
ip wccp {web-cache | service-number} redirect {out | in}
Syntax Description
web-cache Enables the web cache service. service-number Identification number of the Content Engine service group being controlled by a router. The number can be from 0 to 99. The reverse proxy service is indicated by a value of 99. redirect Enables packet redirection checking on an outbound or inbound interface. out Specifies packet redirection on an outbound interface. in Specifies packet redirection on an inbound interface.
Defaults
Redirection checking on the interface is disabled.
Command Types
Interface configuration
Usage Guidelines
Redirection can be specified for outbound interfaces or inbound interfaces. Inbound traffic can be configured to use Cisco Express Forwarding (CEF), distributed Cisco Express Forwarding (dCEF), fast forwarding, or process forwarding.
Configuring WCCP for redirection for inbound traffic on interfaces allows you to avoid the overhead associated with CEF forwarding for outbound traffic. Setting an output feature on any interface results in the slower switching path of the feature being taken by all packets arriving at all interfaces. Setting an input feature on an interface results in only those packets arriving at that interface taking the configured feature path; packets arriving at other interfaces will use the faster default path.
Configuring WCCP for inbound traffic also allows packets to be classified before the routing table lookup, which translates into faster redirection of packets.
|
Note This command has the potential to affect the ip wccp redirect exclude in command. If you have ip wccp redirect exclude in set on an interface and you subsequently configure the ip wccp redirect in command, the exclude in command is overridden. The opposite is also true: configuring the exclude in command overrides the redirect in command. |
Command History
12.0(3)T This command was introduced. 12.0(11)S The in keyword was added to the 12.0 S release train. 12.1(3)T The in keyword was added to the 12.1 T release train.
Release
Modification
Examples
The following example shows a configuration session in which reverse proxy packets on Ethernet interface 0 are being checked for redirection and redirected to a Cisco Content Engine:
Router# configure terminal
Router(config)# ip wccp 99
Router(config)# interface ethernet 0
Router(config-if)# ip wccp 99 redirect out
The following example shows a configuration session in which HTTP traffic arriving on interface 0/1 is redirected to a Cisco Cache Engine:
Router# configure terminal
Router(config)# ip wccp web-cache
Router(config)# interface ethernet 0/1
Router(config-if)# ip wccp web-cache redirect in
Related Commands
ip wccp redirect exclude in Configures an interface to enable or disable redirection of packets received on an interface.
Command
Description
To configure the WCCP version number, use the ip wccp version global configuration command. The default WCCP version is Version 2. Use this command to override the default.
ip wccp version {1 | 2}
Syntax Description
1 Enables WCCP Version 1. 2 Enables WCCP Version 2.
Defaults
The default is Version 2.
Command Modes
Global configuration
Command History
12.0(5)T This command was introduced.
Release
Modification
Examples
ip wccp version 1
To display status about any ip wccp direct commands configured on an interface, use the show ip interface EXEC command.
show ip interface [type-number]
Syntax Description
type-number (Optional) The interface number whose status is being displayed.
Defaults
No default behavior or values
Command Modes
EXEC
Command History
10.0 This command was introduced. 12.0 This command was enhanced. 12.0(3)T This command was enhanced to include the status of ip wccp redirect out and ip wccp redirect exclude in commands.
Release
Modification
Usage Guidelines
The Cisco IOS software automatically enters a directly connected route in the routing table if the interface is usable. A usable interface is one through which the software can send and receive packets. If the software determines that an interface is not usable, it removes the directly connected routing entry from the routing table. Removing the entry allows the software to use dynamic routing protocols to determine backup routes to the network (if any).
If the interface can provide two-way communication, the line protocol is indicated to be up. If the interface hardware is usable, the interface is indicated to be up.
If you specify an optional interface type, you will see information on that specific interface only.
If you specify no optional arguments, you will see information on all the interfaces.
When an asynchronous interface is encapsulated with Point-to-Point Protocol (PPP) or Serial Line Internet Protocol (SLIP), IP fast switching is enabled. A show ip interface command on an asynchronous interface encapsulated with PPP or SLIP displays a message indicating that IP fast switching is enabled.
Examples
The following example displays output from the show ip interface command, using the interface e3/0:
show ip interface e3/0
Ethernet3/0 is up
Internet address is 17.1.1.38/24
Broadcast address is 255.255.255.255
Address determined by non-volatile memory
MTU is 1500 bytes
Helper address is not set
Directed broadcast forwarding is enabled
Outgoing access list is not set
Inbound access list is not set
Proxy ARP is enabled
Security level is default
Split horizon is enabled
ICMP redirects are always sent
ICMP unreachables are always sent
ICMP mask replies are never sent
IP fast switching is enabled
IP fast switching on the same interface is disabled
IP Optimum switching is enabled
IP multicast fast switching is enabled
Router Discovery is disabled
IP output packet accounting is disabled
IP access violation accounting is disabled
TCP/IP header compression is disabled
Probe proxy name replies are disabled
Gateway Discovery is disabled
Policy routing is disabled
Network address translation is disabled
WCCP Redirect outbound is enabled
WCCP Redirect exclude is disabled
Table B-1 describes the fields shown in the display.
| Field | Description |
|---|---|
Ethernet 3/0 is up | Indicates the status of an interface. If the interface hardware is usable, the interface is marked "up." For an interface to be usable, both the interface hardware and line protocol must be up. |
Internet address | Shows the IP address of the interface. |
Broadcast address | Shows the broadcast address. |
Address determined by | Indicates how the IP address of the interface was determined. |
MTU | Shows the maximum transmission unit (MTU), or the maximum size of packets allowed to be transmitted from the router to a Content Engine. |
Helper address | Shows a helper address, if one has been set. |
Directed broadcast forwarding | Shows a secondary address, if one has been set. |
Outgoing access list | Indicates whether the interface has an outgoing access list set. |
Inbound access list | Indicates whether the interface has an incoming access list set. |
Proxy ARP | Indicates whether proxy Address Resolution Protocol (ARP) is enabled for the interface. |
Security level | Specifies the default IPSO security level for this interface. |
Split horizon | Specifies that routing updates sent to a particular neighbor router should not contain information about routes that were learned from that neighbor. |
ICMP redirects | Indicates whether Internet Control Message Protocol (ICMP) redirects will be sent on this interface. |
ICMP unreachables | Indicates whether unreachable messages will be sent on this interface. |
ICMP mask replies | Specifies whether mask replies will be sent on this interface. |
IP fast switching | Indicates whether fast switching has been enabled for this interface. It is generally enabled on serial interfaces, such as this one. |
IP fast switching on the same interface | Indicates whether fast switching has been disabled for this interface. It is generally enabled on serial interfaces, such as this one. |
IP Optimum switching | Indicates whether the IP optimum switching feature has been turned on. |
IP multicast fast switching | Indicates whether the IP multicast fast switching feature has been turned on. |
Router Discovery | Indicates whether the Cisco Discovery Protocol has been turned off. |
IP output packet accounting | Indicates whether the output packet counter has been turned off. |
IP access violation accounting | Indicates whether the feature that counts unauthorized access events on the router has been turned off. |
TCP/IP header compression | Indicates whether compression is enabled or disabled. |
Probe proxy name replies | Indicates whether HP Probe proxy name replies are generated. |
Gateway Discovery | Indicates whether the gateway discovery option has been turned off. |
Policy routing | Indicates whether the policy routing option has been turned off. |
Network address translation | Indicates whether the status of the network address translation feature has been enabled or disabled. |
WCCP Redirect outbound | Indicates whether packets received on an interface are redirected to a Content Engine. This field can be enabled or disabled. |
WCCP Redirect exclude | Indicates whether packets targeted for an interface will be excluded from being redirected to a Content Engine. This field can be enabled or disabled. |
Related Commands
show ip wccp Displays global statistics related to the Web Cache Communication Protocol feature.
Command
Description
To display global statistics related to the Web Cache Communication Protocol (WCCP) feature, use the show ip wccp EXEC command.
show ip wccp {web-cache | service-number} [view | detail]
Syntax Description
web-cache Directs the router to display statistics for the web cache service. service-number Identification number of the Content Engine service group being controlled by a router. The number can be from 0 to 99. The reverse proxy service is indicated by a value of 99. The custom web cache service is indicated by a value of 98. view (Optional) Directs the router to display statistics for the WCCP view configuration. detail (Optional) Directs the router to display statistics for the WCCP detail configuration.
Defaults
No default behavior or values
Command Modes
EXEC
Command History
11.1 CA and 11.2 P This command was introduced. 12.0(3)T The user was allowed to query the router for the current global configuration information in use by either a single service or all services.
Release
Modification
Usage Guidelines
Use the clear ip wccp command to reset the counter for the "Total Packets Redirected" information.
Examples
The following example displays output from the show ip wccp command:
show ip wccp
Global WCCP Information:
Service Name: web-cache:
Number of Content Engines:1
Number of Routers:1
Total Packets Redirected:213
Redirect access-list: no_linux
Total Packets Denied Redirect:88
Total Packets Unassigned:-none-
Group access-list:0
Total Messages Denied to Group:0
Total Authentication failures:0
Service Name: 1
Number of Content Engines:1
Number of Routers:2
Total Packets Redirected:198
Redirect access-list:-none-
Total Packets Denied Redirect:0
Total Packets Unassigned:0
Group access-list:11
Total Messages Denied to Group:0
Total Authentication failures:0
Table B-2 describes the fields shown in the display.
| Field | Description |
|---|---|
Service Name | Service that is detailed in the display output. |
Number of Content Engines | Number of Content Engines using the router as their home router. |
Number of Routers | Number of routers in the service group. |
Total Packets Redirected | Total number of packets redirected by the router. |
Redirect access-list | Name or number of the access list that determines which packets will be redirected. |
Total Packets Denied Redirect | Total number of packets that were not redirected because they did not match the access list. |
Total Packets Unassigned | Number of packets that were not redirected because they were not assigned to any Content Engine. Packets may not be assigned during initial discovery of Content Engines or when a Content Engine is dropped from a cluster. |
Group access-list | Content Engine that is allowed to connect to the router. |
Total Messages Denied to Group | Number of messages disallowed by the router because they did not meet all the requirements of the service group. |
Total Authentication failures | Number of password authentication failures. |
The following example displays output from the show ip wccp web-cache detail EXEC command. This command displays Content Engine and WCCP router statistics for a particular service group:
show ip wccp web-cache detail
WCCP Router information:
IP Address 172.31.88.10
Protocol Version:2.0
WCCP Cache-Engine Information
IP Address:172.31.88.11
Protocol Version:2.0
State:Usable
Initial Hash Info:AAAAAAAAAAAAAAAAAAAAAAAAAA
AAAAAAAAAAAAAAAAAAAAAAAAAA
Assigned Hash Info:FFFFFFFFFFFFFFFFFFFFFFFFFF
FFFFFFFFFFFFFFFFFFFFFFFFFF
Hash Allotment:256 (100.00%)
Packets Redirected:21345
Connect Time:00:13:46
Table B-3 describes the fields shown in the display.
| Field | Description |
|---|---|
WCCP Router information | Header for the area that contains fields for the IP address and version of WCCP associated with the router connected to the Content Engine in the service group. |
IP Address | IP address of the router connected to the Content Engine in the service group. |
Protocol Version | Version of WCCP being used by the router in the service group. |
WCCP Cache-Engine information | Fields for information on Content Engines. |
IP Address | IP address of the Content Engine in the service group. |
Protocol Version | Version of WCCP being used by the Content Engine in the service group. |
State | Indicates whether the Content Engine is operating properly and can be contacted by a router and other Content Engines in the service group. |
Initial Hash Info | Initial state of the hash bucket assignment. |
Assigned Hash Info | Current state of the hash bucket assignment. |
Hash Allotment | Percentage of buckets assigned to the current Content Engine. Both a value and a percentage figure are displayed. |
Packets Redirected | Number of packets that have been redirected to the Content Engine. |
Connect Time | Length of time the Content Engine has been connected. |
The following is sample output from the show ip wccp view EXEC command. In this case, the service number 1 has been specified.
show ip wccp service 1 view
WCCP Router Informed of:
192.168.88.10
192.168.88.20
WCCP Content Engines Visible
192.168.88.11
192.168.88.12
WCCP Content Engines Not Visible:
-none-
If any Content Engine is displayed under the WCCP Content Engines Not Visible field, the Content Engine needs to be reconfigured to add this router to it.
Table B-4 describes the fields shown in the display.
| Field | Description |
|---|---|
WCCP Routers Informed of | List of routers detected by the current router. |
WCCP Content Engines Visible | List of Content Engines that are visible to the router and other Content Engines in the service group. |
WCCP Content Engines Not Visible | List of Content Engines in the service group that are not visible to the router and other Content Engines in the service group. |
Related Commands
ip wccp detail Directs a router to enable or disable the support for a service group.
Command
Description
Posted: Tue Nov 12 15:52:13 PST 2002
All contents are Copyright © 1992--2002 Cisco Systems, Inc. All rights reserved.
Important Notices and Privacy Statement.