Determining network between routers for OSPF

[MG33]

Hi I am trying to work out the network IP between 2 routers so that I can configure OSPF. I understand I must 'AND' the IP address of an interface with its subnet, but how do I know which IP address to use between 2 routers?

Is it to do with which end is DCE?

[Joseph W. Doherty · Accepted solution]

Hmm, it took me a while to figure out what, I think (?), @TotallyTodd is describing.  Assuming I do correctly understand his point, perhaps my difficulty in understanding his post was because what he is describing I didn't immediately (or still) see as directly relevant to OP or other postings in this thread.

Anyway, I think what he is reminding us of, is an address mask used in an OSPF network statement doesn't necessary become the network mask OSPF advertises for an interface's network; which is, of course, correct.

Again assuming I understand Totally's point, then:

interface e0
ip address 192.168.1.1 255.255.255.0 !i.e. /24 network

routing ospf 10 !any of the following would advertise the above's 192.168.1.0/24 network
network 192.168.1.1 0.0.0.0 area #
network 192.168.1.1 0.0.0.255 area #
network 192.168.1.1 0.0.255.255 area #
network 192.168.1.1 0.255.255.255 area #
network 192.168.1.1 255.255.255.255 area #

[TotallyTodd]

Totally

[MG33]

Cheers everyone, I got sorted!