L2 switching between 2 routers

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Apr 14th, 2012
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I have a pair of 3945 routers.  Each router has a SM-ES3G-16-P 16-port switch L2/L3 card.  I need basic L2 switch (or port channel between each router via these switch port cards.

I need to set up HSRP between a GE port on each router to an external firewall using static routing.  I want to set up resiliency between these router GE ports that directly connect to the firewalls so that if Router 1/Firewall 1 fails, router 2/firewall2 takes over.  Right now, each router thinks it is the active HSRP on their respective GE, since no HSRP keep alives are communicated between the routers (yet).   Hopefully, by establishing a L2/Port-channel between the switch cards, HSRP keep alives will pass between routers.  (FWs act as clustered pair using a HSRP IP address for the active FW)

I also have a pair of HWIC-4ESW cards being shipped out next week to try in lieu of those SM-ES3G-16-P cards.

Any suggestions how to get 2 routers communicating HSRP keep alives acess a pair of embedded L@ switch cards on the routers?

High level:

RTR1 GE1/0 directly connected to FW1 GE1/0

RTR2 GE1/0 directly connected to FW2 GE1/0

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glen.grant Sun, 04/15/2012 - 01:53
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    The l3 routing will have to be on those switchcards if it is going to work correctly if  you tie the switchcards together and will limit you to 100 meg if you use the hwic-4esw.  They are logically separate from the builtin gig  ports . 

Jeff Van Houten Sun, 04/15/2012 - 06:32
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As glen pointed out you already have more than enough switch capability. Why not create a trunk with a physical cable between the two switches then link your firewall interfaces to a common vlan shared by those same switches? A diagram of what you are trying to do would probably help.

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wayne.berthold@... Mon, 04/16/2012 - 19:52
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I've added the router and switch configurations for both routers.  I can ping from either switch to the other switch, but not to the other router.  I have established a Port Channel to support this, but it still does not work as required.  What am I missing in the config?


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