Etherchannel/HSRP Design Question

We currently have a 3845 router which has two connections.

G0/0 - Connects to internal core switch (10.10.10.2)
G0/1 - shut
G0/2 - shut
G0/3 - Connects to provider switch (internet) (1.1.1.1)

We are upgrading some equipment. Our internal switch will be replaced with 2 3750's in a stack. And we are also getting a second 3845 for failover. I'm planning on creating two HSRP instances, one for inside and one for outside. And also create an etherchannel to the 3750s.

Is this possible?

G0/0 - Connects to 3750-1
G0/1 - Connects to 3750-2
G0/2 - shut
G0/3 - Connects to provider switch (internet)
Etherchannel1 - Connects to 3750-1 and 3750-2 (10.10.10.2)

Since we will use HSRP, we will be utilizing several IP's, both private and public.

Find more posts tagged with

Comments

networker050184

I'd check and make sure everything you are using supports L3 etherchannel. I'm not sure off the top of my head, but I'm sure some googling and the Cisco Feature Navigator - Cisco Systems should get you all the info you need.

mzinz

networker050184 wrote: »

I'd check and make sure everything you are using supports L3 etherchannel. I'm not sure off the top of my head, but I'm sure some googling and the Cisco Feature Navigator - Cisco Systems should get you all the info you need.

Ok, cool. I know the 3750 does, so as long as the 3845 supports that, I'm good.

But design wise - this setup should work fine, and I assume is fairly typical?

Edit: Oh, I see. The issue isn't supporting Etherchannel, it's the fact that I'm using a L3 link. I found a document (http://www.cisco.com/en/US/prod/collateral/routers/ps5855/prod_white_paper0900aecd806f698a.pdf) that says the 3845 supports it, and it references a 3750, so I think I'm OK.

mzinz

Tried to lab this when I got home and ran into some trouble.

It looks like it is not possible to configure Etherchannel with routed ports at all. It CAN be done with the switchport modules (such as HWIC-4ESW).

networker050184

mzinz wrote: »

Tried to lab this when I got home and ran into some trouble.

It looks like it is not possible to configure Etherchannel with routed ports at all. It CAN be done with the switchport modules (such as HWIC-4ESW).

Thats what I thought would be the case. You can always just go with two seperate routed ports and load balance over them.

deth1k

3750 do support Layer3 EtherChannels with the right IOS image but why would you need to run it with your router? It will not provide any more redundancy than having two connections from each switch to each router.