What HSRP interface will be used as network statement in OSPF

[Hasrat Raja]

Hi,

I am setting up 2 switches with OSPF & HSRP, using /32 for each interface under OSPF, will standby interface IP used on both switches or physical interface IP under OSPF ?

thanks

hasrat

[Jon Marshall]

Not sure I follow what you mean.

OSPF does not use VIPs, it is uses the physical interface IPs but you won't be runnning OSPF on the HSRP interfaces, you will simply be advertising the subnet into OSPF.

Can you clarify.

Jon

[Hasrat Raja]

Hi Jon,

Correct I will be advertising subnets in OSPF, I am using actual interface IP with /32 mask not the whole /23 subnet. which address should I add under ospf, physical or virtual ?

thanks

[Jon Marshall · Accepted solution]

So you mean your network statement under OSPF is just using the specific interface IP ?

If so use physical IPs because that simply tells OSPF to start on that interface and then it will advertise the IP subnet associated with that interface.

Jon

[Hasrat Raja]

Thank you for the response, I have searched could not find a document, can you please share if you know of any

hasrat

[Jon Marshall]

I don't have a document but this is basic IGP behviour.

The network statement under an IGP simply tells it which interfaces to run on.

Once the IGP starts on that interface it then uses the subnet and subnet mask associated with that interface and advertises them out.

Jon

[Hasrat Raja]

Thank you for clarification, appreciate your help