Web Cache Communication Protocol Version 1

i p wccp enable

To enable the router to support WCCP, use the ip wccp enable global configuration command. The no form of this command disables support for WCCP.

ip wccp enable

no ip wccp enable

Syntax Description

This command has no arguments or keywords.

Defaults

WCCP is disabled on the router.

Command Modes

Global configuration

Command History

This command first appeared in Cisco IOS Release 11.2 P and Release 11.1 CA.

Usage Guidelines

This command and the ip web-cache redirect interface command are the only commands required to start redirecting requests to the Content Engine using WCCP. To see whether WCCP is enabled on the router, use the show ip wccp command.

When this command is enabled but the ip web-cache redirect command is disabled, the router is aware of Content Engines but does not use them.

Use the ip wccp redirect-list command to limit the redirection of packets to those matching an access list.

Examples

The following example configures a router to support WCCP and redirects web-related packets from Ethernet interface 0 to the Content Engine:

Router# configure terminal

Router(config)# ip wccp enable

Router(config)# interface Ethernet 0

Router(config-if)# ip web-cache redirect

Router(config-if)# end

Router#
%SYS-5-CONFIG_I: Configured from console by console.

Related Commands Related Commands

ip wccp redirect-list

ip wccp redirect-list

To specify which packets are redirected to a Content Engine, use the ip wccp redirect-list global configuration command. The no form of this command enables redirection of all packets.

ip wccp redirect-list {number | name}

Syntax Description

number	Standard or extended IP access list number from 1 to 199.
name	Standard or extended IP access list name. This argument is only available in Cisco IOS Release 11.2 P.

Defaults

All HTTP packets are redirected to the Content Engine.

Command Modes

Global configuration

Command History

This command first appeared in Cisco IOS Release 11.2 P and Release 11.1 CA.

Usage Guidelines

Use this command to specify which packets should be redirected to the Content Engine. When WCCP is enabled but this command is not configured, all web-related packets are redirected to the Content Engine. When you enter this command, only packets that match the access list are redirected.

Some web sites use the source IP address of packets for authentication. The Content Engine uses its own IP address when sending requests to web sites. Thus, the requests from the Content Engine may not be authenticated. Use this command to bypass the Content Engine in these cases.

Use the ip wccp enable and ip web-cache redirect commands to configure WCCP.

Examples

The following example configures a router to redirect web-related packets without a destination of 192.168.196.51 to the Content Engine:

Router# configure terminal

Router(config)# access-list 100 deny ip any host 192.168.196.51

Router(config)# access-list 100 permit ip any any

Router(config)# ip wccp enable

Router(config)# ip wccp redirect-list 100

Router(config)# interface Ethernet 0

Router(config-if)# ip web-cache redirect

Router(config-if)# end

Router#
%SYS-5-CONFIG_I: Configured from console by console.

Related Commands

ip web-cache redirect

To instruct an interface to check for appropriate outgoing packets and redirect them to a Content Engine, use the ip web-cache redirect interface configuration command. The no form of this command disables the redirection of messages to the Content Engine.

ip web-cache redirect

no ip web-cache redirect

Syntax Description

This command has no arguments or keywords.

Defaults

The interface does not redirect messages to the Content Engine.

Command Modes

Interface configuration

Command History

This command first appeared in Cisco IOS Release 11.2 P and Release 11.1 CA.

Usage Guidelines

This command and the ip wccp enable interface command are the only commands required to start redirecting requests to the Content Engine using WCCP.

Examples

The following example configures a router to support WCCP and redirects web-related packets from Ethernet interface 0 to the Content Engine:

Router# configure terminal

Router(config)# ip wccp enable

Router(config)# interface Ethernet 0

Router(config-if)# ip web-cache redirect

Router(config-if)# end

Router#
%SYS-5-CONFIG_I: Configured from console by console.

Related Commands

ip wccp redirect-list

show ip interface

show ip interface

To display the usability status of interfaces configured for IP, use the show ip interface EXEC command.

show ip interface [type number]

Syntax Description

type	(Optional.) Interface type.
number	(Optional.) Interface number.

Defaults

No default behavior or values

Command Modes

EXEC

Command History

This command first appeared in Cisco IOS Release 10.0.

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 marked "up." If the interface hardware is usable, the interface is marked "up."

If you specify an optional interface type, you will see information about that specific interface only.

If you specify no optional arguments, you will see information about all of 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 is sample output from the show ip interface command:

Router# show ip interface

 
Ethernet0 is up, line protocol is up
  Internet address is 172.168.78.24, subnet mask is 255.255.255.240

  Broadcast address is 255.255.255.255

  Address determined by non-volatile memory

  MTU is 1500 bytes

  Helper address is not set

Secondary address 172.31.255.255, subnet mask 255.255.255.0
  Directed broadcast forwarding is enabled

  Multicast groups joined: 224.0.0.1 224.0.0.2

  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 SSE switching is disabled

  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

  Web Cache Redirect is enabled

Table A-1 describes the fields shown in the display.

Table A-1: Field Descriptions—show ip interface Command

Field	Description

Ethernet0 is up	If the interface hardware is usable, the interface is marked "up." For an interface to be usable, both the interface hardware and the line protocol must be up.
Line protocol is up	If the interface can provide two-way communication, the line protocol is marked "up." For an interface to be usable, both the interface hardware and the line protocol must be up.
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) value set on the interface.
Helper address	Shows a helper address, if one has been set.
Secondary address	Shows a secondary address, if one has been set.
Directed broadcast forwarding	Indicates whether directed broadcast forwarding is enabled.
Multicast groups joined	Indicates the multicast groups this interface is a member of.
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 IP Security Option (IPSO) security level set for this interface.
ICMP redirects	Specifies whether redirects will be sent on this interface.
ICMP unreachables	Specifies 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	Specifies whether fast switching has been enabled for this interface. It is generally enabled on serial interfaces, such as this one.
IP SSE switching	Specifies whether IP silicon switching engine (SSE) switching is enabled.
Router Discovery	Specifies whether the discovery process has been enabled for this interface. It is generally disabled on serial interfaces.
IP output packet accounting	Specifies whether IP accounting is enabled for this interface and what the threshold (maximum number of entries) is.
TCP/IP header compression	Indicates whether compression is enabled or disabled.
Probe proxy name	Indicates whether HP probe proxy name replies are generated.
Web Cache Redirect	Indicates whether HTTP packets are redirected to a Content Engine.

show ip wccp

To display global statistics related to WCCP, use the show ip wccp EXEC command.

show ip wccp

Syntax Description

This command has no arguments or keywords.

Defaults

No default behavior or values

Command Modes

EXEC

Command History

This command first appeared in Cisco IOS Release 11.2 P and Release 11.1 CA.

Usage Guidelines

Use the clear ip wccp command to reset the counter for the "Packets Redirected" information.

Examples

The following example shows sample show ip wccp output:

Router# show ip wccp

 
Global WCCP information:
         Number of web-caches:                2
         Total Packets Redirected:            101
         Redirect access-list:                no_linux
         Total Packets Denied Redirect:       88
         Total Packets Unassigned:            0

Table A-2 describes the fields shown in this example.

Table A-2: Field Descriptions—show ip wccp Command

Field	Description

Number of web-caches	Number of Content Engines using the router as their home router.
Total Packets Redirected	Total number of packets redirected by the router.
Redirect access-list	Name or number of the redirect access list. Only packets matching the access list are 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 web cache. Packets are sometimes not assigned during initial discovery of Content Engines or when a Content Engine is dropped from a farm.

Related Commands

ip wccp redirect-list

show ip interface

show ip wccp web-caches

To display information about the router's known Content Engines, use the show ip wccp web-caches EXEC command.

show ip wccp web-caches

Syntax Description

This command has no arguments or keywords.

Defaults

No default behavior or values

Command Modes

EXEC

Command History

This command first appeared in Cisco IOS Release 11.2 P and Release 11.1 CA.

Usage Guidelines

Use the clear ip wccp command to reset the counter for the "Packets Redirected" information.

Examples

The following example shows sample show ip wccp web-caches output:

Router# show ip wccp web-caches

 
WCCP Web-Cache information:
        IP Address:            172.168.88.11
        Protocol Version:      1.0
        State:                 Usable
        Initial Hash Info:     AAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA
                               AAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA
        Assigned Hash Info:    FFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFF
                               FFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFF
        Hash Allotment:        256 (100.00%)
        Packets Redirected:    21345
        Connect Time:          00:13:46

Table A-3 explains the fields shown in this display.

Table A-3: Field Descriptions—show ip wccp web-caches Command

Field	Description

IP Address	IP address of the Content Engine.
Protocol Version	Version of the Web Cache Communication Protocol the Content Engine is running.
State	State of the Content Engine. Possible values are "Usable" and "NOT Usable."
Initial Hash Info	Initial contents of the hash field. The hash field contains information about how the router intends to use the Content Engine.
Assigned Hash Info	Current hash information of the Content Engine. The hash information field contains information about how the router intends to use the Content Engine.
Hash Allotment	Percentage of all possible web servers for which the router redirects HTTP requests to this web cache. In this example, there is only one Content Engine, so all HTTP requests are redirected to it.
Packets Redirected	Number of packets redirected to this Content Engine.
Connect Time	Indicates how long the Content Engine has used this router as its home router.

Related Commands

show ip interface