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New Member

how to configure HSRP

We have a PIX firewall that is connected to 2 perimeter Cisco 2610 routers. The routers are running HSRP and each is connected to its own ISP through a full T1 line. What we would like to do is to use one of the routers for transmit only and the other for receive only. I have figured they would have to be on a HD connection to the ISP, but how do I force a router for either transmit or receive?

Thanks.

4 REPLIES
Cisco Employee

Re: how to configure HSRP

After you have your routing to the ISP worked out you can force your "Transmit" router to HSRP active with the 'standby priority' command. Just give it a value higher than its peer (eg, 200 vs 100). This all assumes your PIX is forwarding the a default next-hop of the HSRP standby ip.

http://www.cisco.com/pcgi-bin/Support/browse/psp_view.pl?p=Technologies:HSRP

New Member

Re: how to configure HSRP

Thanks for your response.

The PIX is indeed forwarding the default next-hop of the HSRP standby ip. However, how do I force a router to transmit or receive only?

Thanks again.

New Member

Re: how to configure HSRP

Or, I guess, a better way of putting it is how to configure the inbound traffic to traverse one circuit but not the other? Would tweaking the BGP protocol do it?

Thanks.

Silver

Re: how to configure HSRP

There are various ways you can manipulate your traffic path with BPG. One possibility would be to use Local Preference to influence your outbound path and AS Path Prepending to influence your inbound path (if you connect to the same ISP on both routers a better approach would be to use MED to influence your inbound traffic)

In the following example to influence the outbound path the Outbound Router sets the Local Preference for all routes learnt from the EBGP to 150 and the Inbound Router to 50 (higher number is preferred). When these are exchanges via IBGP both routers will agree on the same outbound router (Local Preference is before AS Path length in the route selection process).

To influence the inbound path the Outbound router prepends two instances of it’s AS number to the AS Path (local routes would then be advertised to the EBGP peer with an AS Path of 64512 64512 64512 by the Outbound router and 64512 by the Inbound router). Upstream ISP’s should then select the shortest AS Path to your routes via the Inbound router.

Outbound traffic now routes via the Outbound router and inbound traffic via the Inbound router.

OUTBOUND ROUTER

router bgp 64512

neighbor route-map SET-LOCAL-PREF in

neighbor route-map SET-AP-PATH-PREPEND out

!

!

route-map SET-LOCAL-PREF permit 10

set local-preference 150

!

!

route-map SET-AP-PATH-PREPEND permit 10

set as-path prepend 64512 64512

!

INBOUND ROUTER

router bgp 64512

neighbor route-map SET-LOCAL-PREF in

!

!

route-map SET-LOCAL-PREF permit 10

set local-preference 50

!

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