|
|
This appendix describes the Web Cache Communication Protocol (WCCP) Version 2 feature. It includes information on the benefits of this new feature, supported platforms, and other information you may need to work with WCCP Version 2.
The Web Cache Communication Protocol (WCCP) feature allows you to use a Cache Engine to handle web traffic, reducing transmission costs and downloading time. This traffic includes user requests to view pages and graphics on World Wide Web servers, whether internal or external to your network, and the replies to those requests. When a user requests a page from a web server (located in the Internet), the router sends the request to a Cache Engine. If the Cache Engine has a copy of the requested page in storage, the Cache Engine sends the user that page. Otherwise, the Cache Engine retrieves the requested page and the objects on that page from the web server, stores a copy of the page and its objects, and forwards the page and objects to the user.
WCCP transparently redirects Hypertext Transfer Protocol (HTTP) requests going to the intended server to a Cache Engine. End users do not know that the page came from the Cache Engine rather than the originally requested web server.
WCCP Version 2 now contains the following new features:
WCCP Version 2 enables a series of Cache Engines, called a Cache Engine cluster, to connect to multiple routers. This feature provides redundancy and a more distributed architecture for instances when a Cache Engine needs to connect to a large number of interfaces. This strategy also has the benefit of keeping all the Cache 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 D-1 illustrates how this configuration appears.
The following sequence of events details how this process works:
1. Each Cache Engine records the IP address of the router servicing the cluster.
2. The Cache 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 Cache Engines, establishing that each can connect to the other in the cluster, providing a view or a list of Cache Engine addresses in the cluster, indicating that each can recognize each other.
4. Once the view has been established, one Cache Engine is designated as the lead and indicates to the router how IP packet redirection should be performed. The lead Cache 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, allowing available routers to obtain status as the device that redirects packets for data coming from each of the Cache Engines in the cluster. Figure D-2 illustrates how this configuration appears. You can configure the router to run the web cache service which is a global service that sends content to a large collection of destination World Wide Web servers.
The subset of Cache Engines within a cluster and routers connected to the cluster that are running the same service is known as a service group.
WCCP Version 2 addresses the issue of multiple routers being available to the cluster by allowing a list of routers to be created on the Cache Engine. The Cache Engine sends a notification of its presence to each explicit router address on the router list on the Cache Engine.
The following sequence of events details how this process works:
1. Instead of having one central "home router," each Cache Engine defines a list of routers and stores the list in its memory.
2. Each Cache Engine announces its presence and view of the service group to the list of router IP addresses with which they have been configured. The routers reply with their view which is a list of Cache Engine addresses in the group.
3. Once the view is consistent across all Cache Engines in the cluster, one Cache Engine is designated as the lead and sets the policy that the routers need to deploy in redirecting packets.
Also, you need to configure the router(s) that will become members of the service group and enable the ip wccp command.
Routers and Cache Engines become aware of each other and form a service group using a management protocol. Once the service group has been established, one of the Cache Engines is designated to determine load assignments among the Cache Engines.
If there is a group of Cache Engines, the one seen by all routers and that has the lowest IP address becomes the lead Cache Engine. The role of this Cache Engine is to determine how traffic should be split across Cache Engines. The assignment information is passed to the entire service group from the designated Cache Engine so that the routers of the group can redirect the packets properly and the Cache Engines of the group can manage their load better.
Security between a Cache Engine and a router is now stronger because the Cache Engine's location in a cluster is more strongly circumscribed. WCCP Version 2 provides authentication that enables you to control which routers and Cache Engines become part of the service group using passwords and the HMAC MD5 standard set by the ip wccp [password [0-7] password] command.
Cisco Express Forwarding (CEF) has been integrated into WCCP Version 2 and provides fast packet redirection.
Access to multiple routers provides backup support for a failed connection between a Cache Engine and the router. Multiple routers can access a Cache Engine server cluster.
Security between a Cache Engine and a router is now stronger as the Cache Engine's place in a cluster is more strongly circumscribed. Also authentication is now available using the HMAC MD5 security feature.
CEF provides fast redirection by using more efficient levels of switching.
The following limitations apply to WCCP Version 2:
To understand how WCCP Version 2 works, you must understand concepts associated with the Cache Engine.
IOS versions before 12.0(3)T support only WCCP Version 1. IOS versions between 12.0(3)T and 12.0(5)T support only WCCP Version 2. IOS version 12.0(5)T or later support both WCCP Version 1 and Version 2. In IOS version 12.0(5)T or later, the default WCCP version is Version 2. You can override the WCCP default, by using the global configuration command ip wccp version 1.
If you have WCCP Version 1 configured and attempt to configure any WCCP Version 2 specific features, you will receive a configuration error.
The following platforms are supported:
| PLATFORM | IOS 11.1CA | IOS 11.2P | IOS 12.0(3)T | IOS 12.0(5)T |
|---|---|---|---|---|
Cisco 2500 series | v1 | v1 | v2 | v1/v2 |
Cisco 4000 series | v1 | v1 | v2 | v1/v2 |
Cisco 4500 series | v1 | v1 | v2 | v1/v2 |
Cisco 4700 series | v1 | v1 | v2 | v1/v2 |
Cisco 7200 series | v1 | v1 | v2 | v1/v2 |
Cisco 7500 series | v1 | v1 | v1 | v1/v2 |
For descriptions of supported MIBs and how to use MIBs, see Cisco's MIB web site on CCO at http://www.cisco.com/public/sw-center/netmgmt/cmtk/mibs.shtml.
None
Before you use WCCP Version 2, you must complete the following tasks:
You can configure a router to run the web cache service associated with WCCP Version 2. Perform the following tasks to configure a cluster with multiple routers.
| Step | Command | Purpose |
|---|---|---|
1. | | Turns on the protocol for web caching. |
2. | | Targets an interface number for which a web cache service will run. The interface type can be any IP-based interface (e.g., Ethernet or Fast Ethernet). |
3. | | Enables the check on packets to determine if they qualify to be redirected to a web cache. |
| Step | Command | Purpose |
|---|---|---|
1. | 1. Router(config)# access-list access-list permit ip host host-address | 1. Creates an access list that enables or disables traffic redirection to the Cache Engine. |
2. | | Indicates to the router which IP addresses of the Cache Engines to accept packets from. |
| Step | Command | Purpose |
|---|---|---|
1. | | Sets a password for the Cache Engine the router is trying to access. |
| Step | Command | Purpose |
|---|---|---|
1. | | Creates an access list that enables or disables traffic redirection to the Cache Engine. |
1. | | Sets the access list used to enable redirection |
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 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
no ip route-cache
no ip mroute-cache
!
interface Ethernet1
ip address 10.4.1.1 255.255.255.0
no ip directed-broadcast
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
| Command | Purpose |
|---|---|
| Displays global statistics related to WCCP. |
| Queries the router for information on which Cache Engines of the web-cache service group the router has detected. |
| Displays which devices in the web-cache service group have been detected and which Cache Engines are having trouble becoming visible to all other routers to which the current router is connected. |
| Displays status about whether any ip wccp redirect commands are configured on an interface. |
The following output is displayed when entering the show ip wccp command:
Router# show ip wccp
Global WCCP Information:
Router information: 10.4.1.1
Router Identifier:
Protocol Version: 2.0
Service Identifier: web-cache
Number of Cache 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
This section provides the following configuration examples:
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
To achieve better security, you can notify the router which IP addresses are valid addresses for a Cache Engine attempting to register with the current router, using a standard access list. The following example, shows a standard access list configuration session where the access list number is 10 for some sample hosts:
access-list 10 permit host 11.1.1.1
access-list 10 permit host 11.1.1.2
access-list 10 permit host 11.1.1.3
ip wccp web-cache group-list 10
The following example shows a WCCP Version 2 password configuration session where the password is alabama2:
configure terminal
ip wccp web-cache password alabama2
To disable caching for certain clients, servers, or client/server pairs, you can use WCCP access lists. The following example shows any requests coming from 10.1.1.1 or going to 12.1.1.1 will bypass the cache while all other requests will be serviced normally:
configure terminal
access-list 120 deny tcp host 10.1.1.1
access-list 120 deny tcp any host 12.1.1.1
access-list 120 permit ip any any
ip wccp web-cache redirect-list 120
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 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
no ip route-cache
no ip mroute-cache
!
interface Ethernet1
ip address 10.4.1.1 255.255.255.0
no ip directed-broadcast
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. All other commands used with this feature are documented in the Cisco IOS Release 12.0 command references.
In Cisco IOS Release 12.0(1)T or later, you can search 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 for the web-cache service, use the clear ip wccp EXEC command.
clear ip wccpThis command has no arguments or keywords.
No default behavior or values.
EXEC
| Release | Modification |
|---|---|
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. |
Use the show ip wccp and show ip wccp web-cache detail commands to display WCCP statistics.
clear ip wccp
| Command | Description |
ip wccp | Directs a router to enable or disable the support for the web-cache service. |
show ip wccp | Displays global statistics related to the WCCP feature. |
redirect-list | (Optional) Directs the router to use an access list to control traffic redirected to the web-cache service group. |
access-list | (Optional) A string (not to exceed 64 characters) that is the name of the access list that determines which traffic is redirected to a Cache Engine. |
group-list | (Optional) Directs the router to use an access list to determine which Cache Engines are allowed to participate in the web-cache service group. |
access-list | (Optional) A string (not to exceed 64 characters) that is the name of the access list that determines which Cache Engines are allowed to participate in the web-cache service group. |
password | (Optional) A 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) This value used to encrypt the password for the Cache Engine. |
password | (Optional) The password name that will be combined with the HMAC MD5 value to create security for the connection between the router and the Cache Engine. |
No default behavior or values.
Global configuration
| Release | Modification |
|---|---|
12.0(3)T | This command was introduced. |
The command is disabled by default.
The following example shows a router configured to run the WCCP web cache service:
ip wccp web-cache
To configure an interface to enable or disable excluding packets received on an interface from being redirected to a cache, use the ip wccp redirect exclude in interface configuration command. To disable a router's ability to verify appropriate packets being redirected to a Cache Engine, use the no form of this command.
ip wccp redirect exclude inThis command has no arguments or keywords.
No default behavior or values.
Interface configuration
| Release | Modification |
|---|---|
12.0(3)T | This command was introduced. |
Note that the command 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.
| Command | Description |
ip wccp web-cache | Directs a router to enable or disable the support for the web-cache service group. |
ip wccp web-cache redirect out | Configures an interface to enable or disable a router's ability to verify that appropriate packets are being redirected to a Cache Engine. |
To configure an interface to enable a router's ability to verify that appropriate packets are being redirected to a Cache Engine, use the ip wccp web-cache redirect out interface configuration command. To disable a router's ability to verify appropriate packets being redirected to a Cache Engine, use the no form of this command.
ip wccp web-cache redirect outThis command has no arguments or keywords.
No default behavior or values.
Interface configuration
| Release | Modification |
|---|---|
12.0(3)T | This command was introduced. |
configure terminal
ip wccp web-cache
interface ethernet 0
ip wccp web-cache redirect out
| Command | Description |
ip wccp redirect exclude in | Configures an interface to enable or disable excluding packets received on an interface from being cached. |
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}
1 | Enables WCCP Version 1. |
2 | Enables WCCP Version 2 |
No default behavior or values.
Global configuration
| Release | Modification |
|---|---|
12.0(5)T | This command was introduced. |
ip wccp version 1
To display status about any ip wccp redirect commands configured on an interface, use the show ip interface EXEC command.
show ip interface [type-number]
type-number | (Optional) The interface number whose status is being displayed. |
No default behavior or values.
EXEC
| Release | Modification |
|---|---|
10.0 | This command was first introduced. |
12.0 | This command was enhanced. |
12.0(3)T | This command was enhanced to include status of ip wccp redirect out and ip wccp redirect exclude in commands. |
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 running. If the interface hardware is usable, the interface is indicated to be running.
If you specify an optional interface type, you will see only information on that specific interface.
If you specify no optional arguments, you will see information on all the interfaces.
When an asynchronous interface is encapsulated with Point-to-Point Protocl (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.
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 D-2 describes the fields shown in the example.
| Field | Description |
|---|---|
Ethernet3/0 is up, line protocol is up | 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 is | The IP address of the interface. |
Broadcast address is | Shows the broadcast address. |
Address determined by non-volatile memory | Indicates how the IP address of the interface was determined. |
MTU is 1500 bytes | Maximum Transmission Unit (MTU) or the maximum size of packets allowed to be transmitted from the router to a Cache Engine. |
Helper address is not set | Shows a helper address, if one has been set. |
Directed broadcast forwarding is enabled | Shows a secondary address, if one has been set. |
Outgoing access list is not set | Indicates whether the interface has an outgoing access list set. |
Inbound access list is not set | Indicates whether the interface has an incoming access list set. |
Proxy ARP is enabled | Specifies the IPSO security level set for this interface. |
Security level is default | Specifies the default IPSO security level for this interface. |
Split horizon is enabled | Specifies that routing updates sent to a particular neighbor router should not contain information about routes that were learned from that neighbor. |
ICMP redirects are always sent | Specifies whether redirects will be sent on this interface. |
ICMP unreachables are always sent | Specifies whether unreachable messages will be sent on this interface. |
ICMP mask replies are never sent | Internet Control Message Protocol mask messages that tests node reachability across the network are suppressed. |
IP fast switching is enabled | Specifies 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 is disabled | Specifies whether fast switching has been disabled for this interface. It is generally enabled on serial interfaces, such as this one. |
IP Optimum switching is enabled | The IP Optimum switching feature has been turned on. |
IP multicast fast switching is enabled | The IP multicast fast switching feature has been turned on. |
Router Discovery is disabled | Cisco Discovery Protocol has been turned off. |
IP output packet accounting is disabled | The output packet counter has been turned off. |
IP access violation accounting is disabled | The feature that counts unauthorized access events on the router has been turned off. |
TCP/IP header compression is disabled | Indicates whether compression is enabled or disabled. |
Probe proxy name replies are disabled | Indicates whether HP Probe proxy name replies are generated. |
Gateway Discovery is disabled | The gateway discovery option has been turned off. |
Policy routing is disabled | The policy routing option has been turned off. |
Network address translation is disabled | The status of the network address translation feature. This field can be enabled or disabled. |
WCCP Redirect outbound is enabled | Indicates the status of whether packets received on an interface are redirected to a Cache Engine. This field can be enabled or disabled. |
WCCP Redirect exclude is disabled | Indicates the status of whether packets targeted for an interface will be exluded from being redirected to a Cache Engine. This field can be enabled or disabled. |
| Command | Description |
show ip wccp web-cache detail | Queries the router for information on which other members of the web-cache service group the router has detected. |
show ip wccp web-cache | Displays global statistics related to the Web Cache Communication Protocol feature. |
To display global statistics related to the Web Cache Communication Protocol (WCCP) feature, use the show ip wccp EXEC command.
show ip wccpThis command has no arguments or keywords.
No default behavior or values.
EXEC
| Release | Modification |
|---|---|
11.1 CA/11.2 P | This command was introduced in Cisco IOS Release 11.1 CA and Release 11.2 P. |
|
|
Use the clear ip wccp command to reset the counter for the "Packets Redirected" information.
The following example is sample output from the show ip wccp command:
show ip wccp
Global WCCP Information:
Router information:
Router Identifier: 10.4.1.1
Protocol Version: 2.0
Service Identifier: web-cache
Number of Cache 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
Table D-3 describes the fields shown in the example.
| Field | Description |
|---|---|
Service Identifier | Indicates which service is detailed. |
Number of Cache Engines | Number of Cache Engines using the router as their home router. |
Number of routers | The number of routers in the service group. |
Total Packets Redirected | Total number of packets redirected by the router. |
Redirect access-list | The 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 Cache Engine. Packets may not be assigned during initial discovery of Cache Engines or when a cache is dropped from a cluster. |
Group access-list | Indicates which Cache Engines is allowed to connect to the router. |
Total Messages Denied to Group | Indicates the number of messages disallowed by the router because they did not meet all the requirements of the service group. |
Total Authentication failures | The number of instances where a password did not match. |
| Command | Description |
ip wccp | Directs a router to enable or disable the support for a service group. |
show ip wccp web-cache detail | Queries the router for information on which other members of the web-cache service group the router has detected. |
show ip wccp web-cache view | Displays which Cache Engines in a particular service group have or have not been detected by all other routers to which the current router is connected. |
To query the router for information on which Cache Engines of the web-cache service group the router has detected, use the show ip wccp detail EXEC command.
show ip wccp web-cache detailThis command has no keywords or parameters.
No default behavior or values.
EXEC
| Release | Modification |
|---|---|
11.1 CA/11.2 P | This command was introduced in Cisco IOS Release 11.1 CA and Release 11.2 P. |
12.0(3)T | This command was expanded to indicate the router information. |
The following example displays Cache Engine and Web Cache Communication Protocol (WCCP) router statistics for the web-cache service group:
show ip wccp web-cache detail
WCCP Router information:
IP Address 192.168.88.10
Protocol Version: 2.0
WCCP Cache-Engine Information
IP Address: 192.168.88.11
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 D-4 describes the fields shown in the example.
| Field | Description |
|---|---|
WCCP Router information | Contains fields for information on the router. |
IP Address | The IP address of the router connected to the Cache Engine in the service group. |
Protocol Version | The version of WCCP being used by the router in the web-cache service group. |
WCCP Cache-Engine information | Contains fields for information on Cache Engines. |
IP Address | The IP address of the Cache Engine in the service group. |
Protocol Version | The version of WCCP being used by the Cache Engine in the service group. |
State | Indicates whether the Cache Engine is operating properly and can be contacted by a router and other Cache Engines in the service group. |
Initial Hash Info | The initial state of the hash bucket assignment. |
Assigned Hash Info | The current state of the hash bucket assignment. |
Hash Allotment | The percent of buckets assigned to the current Cache Engine. Both a value and a percent figure are displayed. |
Packets Redirected | The number of packets that have been redirected to the Cache Engine. |
Connect Time | The amount of time the Cache Engine has been connected. |
| Command | Description |
show ip wccp web-cache view | Displays which Cache Engines in a particular service group have or have not been detected by all other routers to which the current router is connected. |
show ip wccp web-cache | Displays global statistics related to the WCCP feature. |
To display which devices in web-cache service group have or have not been detected by all other routers to which the current router is connected, use the show ip wccp view EXEC command.
show ip wccp web-cache viewThis command has no keywords or parameters.
No default behavior or values.
EXEC
| Release | Modification |
|---|---|
12.0(3)T | This command was introduced in Cisco IOS Release 12.0(3)T. |
The following sample output from the show ip wccp web-cache view command:
show ip wccp web-cache view
WCCP Routers Informed of:
192.168.88.10
192.168.88.20
WCCP Cache Engines Visible:
192.168.88.11
192.168.88.12
WCCP Cache Engines Not Visible:
-none-
If any Cache Engine is displayed under the WCCP Cache Engines Not Visible field, the Cache Engine needs to be reconfigured to add this router to it. Table D-5 describes the fields shown in the example.
| Field | Description |
|---|---|
WCCP Routers Informed of | A list of routers detected by the current router. |
WCCP Cache Engines Visible | A list of Cache Engines that are visible to the router and other Cache Engines in the web-cache service group. |
WCCP Cache Engines Not Visible | A list Cache Engines in the service group that are not visible to the router and other Cache Engines in the web-cache service group. |
| Command | Description |
show ip wccp web-cache detail | Queries the router for information on which other members of the web-cache service group the router has detected. |
show ip wccp web-cache | Displays global statistics related to the Web Cache Communication Protocol feature. |
Cache Engine—A device that stores objects being downloaded from the web for future use by the host.
Cache Engine cluster—A collection of Cache Engines that are controlled by one or more routers.
Cisco Express Forwarding (CEF)—A scalable, distributed, Layer 3 switching solution designed to meet performance requirements of the Internet and enterprise networks.
hash buckets—A pool of IP addresses to which individual servers are mapped.
service group—A subset of Cache Engines within a cluster and routers connected to the cluster that are running the same web cache service.
view—A list of addresses of the Cache Engines and routers in the service group.
WCCP Version 1—A protocol that allows you to use a Cache Engine to handle World Wide Web traffic, thus reducing transmission costs and downloading time. The Cache Engines in the cluster can be mapped to only one router.
WCCP Version 2—A protocol that allows you to use a Cache Engine to handle World Wide Web traffic and other services in a similar manner to WCCP Version 1. Specified services can be mapped to multiple routers.
web cache service—A service that handles large collections of destination World Wide Web servers with various IP addresses throughout the network. The network content, rather than being duplicated across all Cache Engines, is assigned to a particular Cache Engine.
Posted: Sat Sep 28 02:31:22 PDT 2002
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