Etherchannel/HSRP Design Question

mzinzmzinz Member Posts: 328
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.
_______LAB________
2x 2950
2x 3550
2x 2650XM
2x 3640
1x 2801

Comments

  • networker050184networker050184 Mod Posts: 11,962 Mod
    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.
    An expert is a man who has made all the mistakes which can be made.
  • mzinzmzinz Member Posts: 328
    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.
    _______LAB________
    2x 2950
    2x 3550
    2x 2650XM
    2x 3640
    1x 2801
  • mzinzmzinz Member Posts: 328
    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).
    _______LAB________
    2x 2950
    2x 3550
    2x 2650XM
    2x 3640
    1x 2801
  • networker050184networker050184 Mod Posts: 11,962 Mod
    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.
    An expert is a man who has made all the mistakes which can be made.
  • deth1kdeth1k Member Posts: 312
    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.
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