WAAS with HSRP

[TCAM]

I am very new to WAAS technology, please forgive me if i ask a dumb question.

I have been reading Cisco Live power point presentation slides and books, it seems that it is not a good idea to configure WAE to use hsrp ip address on head-end WAN router.  Cisco recommendation is to use WAN router's physical interfaces.  I could'nt find a good documentation to explain why?  What is the logic behind this limitation?   Can someone shed lights in here, please?

2nd question - how to implement network redundancy in a Dual WAN routers & Dual ISP environment if WAE can not use WAN's hsrp ip address during a router or circuit failure scenario?

Many thanks!

[Jan Rockstedt · Accepted solution]

Hi,

I am not seeing any problem with HSRP, with GLBP I see problem as the return traffic most go back on to same router.

For dual routers you should use WCCP on the routers and WAEs.

Jan

[Michael Schueler · Accepted solution]

Hi Joe,

WAAS can work perfectly fine with HSRP. When configuring WCCP for traffic redirection to WAAS you just need to consider the following guidelines:

---snip---

When you configure WCCP for use with the Hot  Standby Router Protocol (HSRP), you must configure the WAE with the HSRP  or the Virtual Router Redundancy Protocol (VRRP) virtual router address  as its default gateway, and the WAE WCCP router-list with the primary  address of the routers in the HSRP group.

---snip---

See here (along with further guidelines):

http://www.cisco.com/en/US/docs/app_ntwk_services/waas/waas/v411/configuration/guide/traffic.html#wp1041518

The WCCP router-list needs to contain the primary address of the interfaces of each router in the HSRP group, as WAAS expects the router to reply to its WCCP HERE_I_AM packets with WCCP I_SEE_YOU packets sourced from the IP address mentioned in the WCCP router-list. A router will always use the primary IP address of the interface as source IP address in I_SEE_YOU packets, never an HSRP virtual address. That's why WAAS required the primary address in the WCCP router-list.

As default gateway on WAAS on the other hand, you even should use the HSRP virtual address, so that WAAS sends all outgoing traffic to the active router.

Regarding your second question, WAAS can use HSRP addresses as default-gateway and thus does allow for redundancy.

In addition, you can even instruct WAAS to always return a packet to the same router from which it received this packet using the "egress-method generic-gre" (Catalyst 6500) or "egress-method negotiated-return" options. If you have a good network design, in which packets traversing between routers can never hit a WCCP redirect statement and also the WAE is not in the same VLAN or subnet as the clients, this is not required, though.

Regards,

Michael

[TCAM]

Thanks guys, I very much appreciated your help.