OSPF Neibourship formation on secondary IP

[rohit.kulkarni]

Hi Friends, Just stuck with query in discussion. Please let me know if any one can sort me out.

I have two routers connected on serial link with /24 subnet mask, I have configured primary ip on WAN as 192.168.1.1/24 on R1 and  .2 /24 on R2

While at the same time i do assign .3/24 as secondary ip on same interface on R1 and .4/24 on R2.

Now i advertise this subnet in OSPF, so now my query is OSPF will form neigbourship with primary IP or with secondary ip or with Both

            R1       ===>  R2

192.168.1.1/24  ==> 192.168.1.2 /24

192.168.1.3/24  ==>  192.168.1.4 /24

[David Aicher]

It will not form a relationship with the secondary address.  It is not possible to configure it to do so.

http://www.cisco.com/en/US//tech/tk365/technologies_tech_note09186a0080094050.shtml

That said I am unsure of the reason you need two addresses in the same subnet on the same interface.   Maybe you could explain the reason for doing this?

Regards

Dave Aicher

[Mahesh Gohil]

Hi,

In addition to david...you can announce secondary ip in ospf but adjancency will not form. In your case both primary/secondary is having

same subnet (strange, i have seed for the first time) so nothing different. But if you have different subnet you will be able to announce via ospf

regards

mahesh