Best practice with WCCP flows for WAAS

[Stephane Lefebvre]

Hi,

I have a WAAS SRE 910 module in a 2911 router that intercepts packets from this router with WCCP.

All packets are received by external interface (gi 2/0, connected to a switch with port configured in WCCP vlan), and are sent back to the router via internal interface (gi 1/0 directly connected to the router) :

WAAS# sh interface gi 1/0

Internet Address                    : 10.0.1.1

Netmask                             : 255.255.255.0

Admin State                         : Up

Operation State                     : Running

Maximum Transfer Unit Size          : 1500

Input Errors                        : 0

Input Packets Dropped               : 0

Packets Received                    : 20631

Output Errors                       : 0

Output Packets Dropped              : 0

Load Interval                       : 30

Input Throughput                    : 239 bits/sec, 0 packets/sec

Output Throughput                   : 3270892 bits/sec, 592 packets/sec

Packets Sent                        : 110062

Auto-negotiation                    : On

Full Duplex                         : Yes

Speed                               : 1000 Mbps

WAAS# sh interface gi 2/0

Internet Address                    : 10.0.2.1

Netmask                             : 255.255.255.0

Admin State                         : Up

Operation State                     : Running

Maximum Transfer Unit Size          : 1500

Input Errors                        : 0

Input Packets Dropped               : 0

Packets Received                    : 86558

Output Errors                       : 0

Output Packets Dropped              : 0

Load Interval                       : 30

Input Throughput                    : 2519130 bits/sec, 579 packets/sec

Output Throughput                   : 3431 bits/sec, 2 packets/sec

Packets Sent                        : 1580

Auto-negotiation                    : On

Full Duplex                         : Yes

Speed                               : 100 Mbps

The default route configured in WAAS module is 0.0.0.0/0 to 10.0.1.254 (router interface).

Would it be better that packets leave WAAS module by the external interface (in place of the internal interface) ?

Is there a best practice recommended by Cisco on this ?

Thanks.

Stéphane

[Nicolas Fournier]

Hi Stephane,

We usually advise the following in such scenario with an internal module:

"ip wccp 61 redirect in" the LAN interface.

"ip wccp 61 redirect in" on the WAN one.

"ip wccp redirect exclude in" on the internal interface between the WAAS and the router.

That way, we are sure that no loops are created because of the WCCP redirection.

Regards,

Nicolas

[Stephane Lefebvre]

Hi Nicolas,

OK.

When you mean "internal interface", is it the service module interface (like SM 1/0) or the router interface that is used by WCCP to reach the module ?

Also, is it prefered that intercepted packets leave the module by gi 1/0 (via SM 1/0 router interface) or by gi 2/0 (via switch interface) ?

Thank you,

Regards.

Stéphane

[Nicolas Fournier · Accepted solution]

Hi Stephane,

That is correct, internal interface means SM1/0.

The best way is to have the traffic leaving the module from the internal interface so that we are sure it hits the redirect exclude statement and that we don't crete any loops because of WCCP.

Regards,

Nicolas