OSPF Router ID

[networkinggeek]

Hi Folks,

I am doing a test lab for learning, I created a router process without defining the router ID, so it took the highest IP as its RID. 

Now I shutdown and cleared that interface which it took its RID, but it still keeps that interface IP though I have cleared IP process on both sides. How to clear it so it takes the new RID? 

Q2: 

Neighbor ID Pri State Dead Time Address Interface
10.10.10.1 1 FULL/DR 00:00:34 10.10.10.1 GigabitEthernet3

What is the address part in this command? Isnt it supposed to be its own interface IP address? Its own interface IP is 10.10.10.2. Where does .1 comes from. 

Thanks

[paul driver]

Hello

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@networkinggeek wrote:

Hi Folks,

I am doing a test lab for learning, I created a router process without defining the router ID, so it took the highest IP as its RID. 

Now I shutdown and cleared that interface which it took its RID, but it still keeps that interface IP though I have cleared IP process on both sides. How to clear it so it takes the new RID? 

Q2: 

Neighbor ID Pri State Dead Time Address Interface
10.10.10.1 1 FULL/DR 00:00:34 10.10.10.1 GigabitEthernet3

What is the address part in this command? Isnt it supposed to be its own interface IP address? Its own interface IP is 10.10.10.2. Where does .1 comes from. 

Thanks

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The RID will take as you have stated the highest ip address on the rtr if no loopback interface if configured or you haven't specified the RID manually.

can do a Clear ip ospf process both sides and then it will take the next highest ip on the rtr.

As for the neigbour id that the rid of the neigbour rtr

res
Paul

[networkinggeek]

I did clear the ospf process on both sides but it still keeps the old interface IP as RID even though that interface is already defaulted.

[Meheretab Mengistu]

Hi,
Could you post your configuration? Also, please post the output of "sh ip ospf database".

HTH,
Meheretab

[paul driver]

Hello

If clearing the ospf process doesn't work then removing the opsf process entirely then recreating it would - or specify it manually as a RID in the opsf process

res
Paul

[networkinggeek]

Paul, you are right. Clearing ospf process did not change/update RID even if the interface is purged.

It only updates if I change RID itself in config mode.

I was wondering it will update itself if the interface configs or IP is changed.

Sal

[paul driver]

Hello

If you change the ip addresses of the interface OPSF has selected initially as its RID then NO it wont, But if you clear the opsf process also it will update its RID to that new ip.

res
Paul

[networkinggeek]

I will rerun the scenario in my GNS lab, and get back with configurations.

[paul driver]

Hello

Good stuff , ill look forward to what you discover?

res
Paul