OSPF Router ID

[DerikA]

I have an MX100 set up as a VPN concentrator/hub for our Meraki networks. It is configured with a warm spare. We are then advertising OSPF to a Cisco layer 3 switch so the local network can see all the spoke networks. 

Primary MX100 static IP of 192.168.0.10

Spare MX100 static IP of 192.168.11

Gateway for both 192.168.0.1

Virtual IP of 192.168.0.2

OSPF Router ID is 192.168.0.10

All of this was set up before I arrived.

My question is if the primary MX fails. Will OSPF still be advertised correctly? To me since it is using the static IP for primary MX as the router ID rather than the virtual IP it would fail. Is that correct?

Thanks in advance for any isite.

DerikA

[PhilipDAth]

I would not expect that to have any impact.

[DarrenOC]

Hi @DerikA  switch to the VIP address otherwise as you state OSPF will fail if the primary fails

[PhilipDAth]

>...switch to the VIP address otherwise as you state OSPF will fail if the primary fails

How?  He is using OSPF.  Everything is dynamically advertised.  He doesn't mention any static routes.

[DarrenOC]

Good point @PhilipDAth 

It’s just the way we’ve always implemented MX pairs with the VIP used for everything.

[DerikA]

Correct we do not have any static routes in this situation.

Like I said my worry is if the primary MX dies since the OSPF router ID is the static of the primary the locale networks on my layer 3 switch will lose the spoke networks attached to the hub MX pair.

So just to confirm as a "best practice" it would be best to change the OSPF router ID to the VIP rather than the static of the primary MX, correct?

[PhilipDAth · Accepted solution]

>So just to confirm as a "best practice" it would be best to change the OSPF router ID to the VIP rather than the static of the primary MX, correct?

It will make no difference.  It is just an ID.  It's like a drivers licence.  It has no impact on routing (or driving).

[Inderdeep]

@DerikA Check out for OSPF routing in the link below

https://documentation.meraki.com/MX/Deployment_Guides/VPN_Concentrator_Deployment_Guide