Basic question on how to advertise OSPF routes

[news2010a]

When advertising OSPF routes, do I need to do it using the ip address of the interface + reverse mask or should I use the network ? For example:

Imagine I have the following interface:

int s0/0

ip add 152.1.1.6 255.255.255.252

I want to advertise it as OSPF. I do:

router ospf 100

network 152.1.1.6 0.0.0.0 area 0

My question is, what is the implication of doing this as '152.1.1.6 0.0.0.0' or should I do it instead using the network as:

152.1.1.4 0.0.0.3 area 0

[Edison Ortiz]

Both networks command will advertise the same with the provided interface ip address.

[sundar.palaniappan]

Marlon,

The network command under the OSPF process defines which interfaces participate in OSPF and what area does it belong to. Hence, it doesn't matter whether you are using a wild card mask of 0.0.0.0 with the IP of the interface or a less specific WC mask, as long as the interface that you want to run OSPF is covered in the network statement.

However, using a less specific wild card mask contains the risk of including an interface to be assigned to an incorrect area etc. Hence, the better method is to use a wild card mask of 0.0.0.0 with the interface IP to avoid any unexpected mistakes. There's no downside in configuring this way.

Hope this helps!

Sundar

[sbdear]

hai

152.1.1.6 is the only addrs advertised , 0.0.0.0 means exactly matches the single ip addrs