HSRP NEXUS

I was curious if a separate HSRP Group should be employed for each SVI on a Core Nexus Switch.  See below.

Should each Vlan have a separate HSRP instance or would one or two instances for HSRP be adequate for 10 or 20 Vlans??

interface Vlan3
  no shutdown
  ip address 131.133.134.131/27
  ip ospf authentication message-digest
  ip ospf message-digest-key 1 md5 3 9125d59c18a9b015
  ip router ospf 10 area 0.0.0.0
  hsrp version 2
  HSRP 3
    preempt
    priority 120
    ip 131.133.134.129

interface Vlan6
  ip address 131.133.134.163/27
  ip ospf authentication message-digest
  ip ospf message-digest-key 1 md5 3 9125d59c18a9b015
  ip router ospf 10 area 0.0.0.0
  hsrp version 2
  HSRP 6
    preempt
    priority 120
    ip 131.133.134.161

interface Vlan7
  ip address 131.133.134.195/27
  ip ospf authentication message-digest
  ip ospf message-digest-key 1 md5 3 9125d59c18a9b015
  ip router ospf 10 area 0.0.0.0
  hsrp version 2
  HSRP 7
    preempt
    priority 120
    ip 131.133.134.193
sectelAsked:
Who is Participating?
I wear a lot of hats...

"The solutions and answers provided on Experts Exchange have been extremely helpful to me over the last few years. I wear a lot of hats - Developer, Database Administrator, Help Desk, etc., so I know a lot of things but not a lot about one thing. Experts Exchange gives me answers from people who do know a lot about one thing, in a easy to use platform." -Todd S.

Craig BeckCommented:
Each VLAN needs its own HSRP instance - you have to configure the instance in the SVI config.  Further to this you can only set one standby IP per HSRP instance so you can't use the same instance for more than one subnet.

You can have multiple HSRP instances on one VLAN though using MHSRP.

Experts Exchange Solution brought to you by

Your issues matter to us.

Facing a tech roadblock? Get the help and guidance you need from experienced professionals who care. Ask your question anytime, anywhere, with no hassle.

Start your 7-day free trial
Jordan MedlenCommented:
If you're looking to route between VLANs, then you'll need an IP address configured on each SVI for said VLAN. If you want first hop redundancy for each SVI acting as a gateway, then you'll want to configure a separate HSRP instance for each also.

Aside from that, I would suggest using GLBP instead of HSRP in order to load-balance traffic going through each switch. GLBP is similar in configuration to HSRP. You can read more here...

http://www.cisco.com/en/US/docs/ios-xml/ios/ipapp_fhrp/configuration/12-4/fhp-glbp.html
sectelAuthor Commented:
Apparently most platforms will not support more than 256 HSRP instances ...what do you do if you have more than 256 Vlan's
Your Guide to Achieving IT Business Success

The IT Service Excellence Tool Kit has best practices to keep your clients happy and business booming. Inside, you’ll find everything you need to increase client satisfaction and retention, become more competitive, and increase your overall success.

Jordan MedlenCommented:
You may want to consider migrating to a traditional hierarchy of core --> distribution --> access where you have layer 3 between your core and distribution layers and deploy your gateways on your distribution devices. This is an assumption of your architecture being a collapsed core design where all layer 3/gateway traffic and subnets reside in the core devices of your infrastructure.
Craig BeckCommented:
You wouldn't generally provide L2 redundancy at the same device for that many VLANs.  As Jordan Medlen said, this is usually separated at the distribution layer.  This allows the scalability you may require.
Jordan MedlenCommented:
To answer the OP's question...

Should each Vlan have a separate HSRP instance or would one or two instances for HSRP be adequate for 10 or 20 Vlans??

...craigbecks reply does answer that question. Is it the only solution, no, but as far as direct replies, it answers the question. I always look to provide better alternative solutions where they exist, rather than only providing the answer to the question given.
Craig BeckCommented:
I didn't say Jordan's comment shouldn't be included in a split.  In the objection I said:

The correct answer is ID: 39752167

The selected answer was just a supplement to the initial comment I made, so the OP has just selected any comment by me as the answer in order to acknowledge that I was correct and award points.

The points awarded were significantly less than the assist too
It's more than this solution.Get answers and train to solve all your tech problems - anytime, anywhere.Try it for free Edge Out The Competitionfor your dream job with proven skills and certifications.Get started today Stand Outas the employee with proven skills.Start learning today for free Move Your Career Forwardwith certification training in the latest technologies.Start your trial today
Networking Hardware-Other

From novice to tech pro — start learning today.