3750 Stack w/ HSRP to Router

[loren.anuszewski]

Hi,

I'm in the process of swapping out a couple routers with a 3750 stack.  The previous setup used 2 routers at one location (the ones being replaced) and a third at an offsite location, so between the three they all have a network connection with HSRP.   After much searching and reading through the Cisco docs I've found this discussion which appears to be similar HERE .  If my understanding is corrrect I believe I have a couple options because I still need the 2 connections to that backup router with HSRP.

1. create a VLAN on the stack with HSRP on it and have a port on each (ie. G1/0/48 and G2/0/48) configured with switchport access to the VLAN.

     interface vlan100

          ip address 10.10.10.1 255.255.255.0

          standby 3  priority 110

     interface GigabitEthernet 1/0/48

          switchport access vlan 100

     interface GigabitEthernet 2/0/48

          switchport access vlan 100

OR...

2. create an etherchannel with LACP for the 2 ports and then assign HSRP to the etherchannel

          interface port-channel 1

          no switchport

          ip address 10.10.10.1 255.255.255.0

          standby 3 priority 110

           interface GigabitEthernet 1/0/1

          no switchport

          no ip address

          channel-protocol lacp

          channel-group 1 mode active

          interface GigabitEthernet 2/0/1

          no switchport

          no ip address

          channel-protocol lacp

          channel-group 1 mode active

Is my understanding correct or is there a better way of accomplishing this?

Your insight is greatly appreciated!

[Reza Sharifi]

Hi,

Since the 3750 stack logically is one switch, you don't have to have 2 connections to the backup router.  If you need 2 connections, then portchannel is a better choice, as long as the router also supports portchannel..

HTH

[loren.anuszewski]

Thanks for your reply Reza.  Here is a simplified version of my current setup and what is being replaced.

The router pair is using HSRP together for redundancy and I have other ports among the 3 routers with HSRP configured, so the three as a whole can work together.  I know the 3750 stack will eliminate the need for HSRP on the pair, but I also need to maintain the HSRP across the 3 routers and I do need the two connections still like the following.

So, are you saying you believe my best bet would be to use port-channel on the 3 ports (one per each device) to create this redundancy with HSRP?

Thanks!