Cisco ASR 1000 Series Configuration Manual page 104

IPv6 WCCP VRF Tunnel Interface
tunnel interfaces are not created directly by WCCP, but are created indirectly via a tunnel application
programming interface (API). WCCP does not have direct knowledge of the tunnel interfaces, but can redirect
packets to them, resulting in the appropriate encapsulation being applied to the packets. After the appropriate
encapsulation is applied, the packet is then sent to the content engine.
Note The tunnel interfaces are not used to connect with incoming WCCP GRE return packets.
One tunnel is created for each service group that is using GRE redirection. One additional tunnel is created
to provide an IP address that allows the other tunnel group interfaces to be unnumbered but still enabled for
IPv6.
You can confirm the connection between the tunnels and WCCP by entering the show tunnel groups wccp
command:
Device# show tunnel groups wccp
WCCP : service group 0 in "Default", ver v2, assgnmnt: hash-table
intf: Tunnel0, locally sourced
WCCP : service group 317 in "Default", ver v2, assgnmnt: hash-table
intf: Tunnel3, locally sourced
WCCP : service group 318 in "Default", ver v2, assgnmnt: hash-table
intf: Tunnel2, locally sourced
You can display additional information about each tunnel interface by entering the show tunnel interface
interface-number command:
Device# show tunnel interface t0
Tunnel0
Mode:multi-GRE/IP, Destination UNKNOWN, Source 2001::DB8:1::2
Application ID 2: WCCP : service group 0 in "Default", ver v2, assgnmnt: hash-table
Linestate - current up
Internal linestate - current up, evaluated up
Device# show tunnel interface t1
Tunnel1
Mode:multi-GRE/IP, Destination UNKNOWN, Source 2001::DB8:1::1
Application ID 2: unspecified
Linestate - current up
Internal linestate - current up, evaluated up
Device# show tunnel interface t2
Tunnel2
Mode:multi-GRE/IP, Destination UNKNOWN, Source 2001::DB8:1::1
Application ID 2: WCCP : service group 318 in "Default", ver v2, assgnmnt: hash-table
Linestate - current up
Internal linestate - current up, evaluated up
Device# show tunnel interface t3
Tunnel3
Mode:multi-GRE/IP, Destination UNKNOWN, Source 2001::DB8:1::1
Application ID 2: WCCP : service group 317 in "Default", ver v2, assgnmnt: hash-table
Linestate - current up
Internal linestate - current up, evaluated up
Device#
Note that the service group number shown in the examples is the internal tunnel representation of the WCCP
service group number. Group 0 is the web-cache service. To determine the dynamic services, subtract 256
from the displayed service group number to convert to the WCCP service group number. For interfaces that
are used for redirection, the source address shown is the WCCP router ID.
IP Application Services Configuration Guide, Cisco IOS XE Release 3S (Cisco ASR 1000)
96
WCCPv2—IPv6 Support