OSPF advertisement question

[mmercaldieze]

I am going to be setting up OSPF in my network and it has been while since I have done OSPF from the ground up.

if my address associated with the ospf link is 1.1.1.1 /24 and I ahve 3 other networks configured on it:

192.168.1.0/24

192.168.2.0/24

192.168.3.0/24

when I setup the ospf statement to advertise the routes do I just need the statement:

network 1.1.1.1 0.0.0.0 area 0

or do I need to do 

network 1.1.1.0 0.0.0.255 area 0

network 192.168.1.0 0.0.0.255 area 0

network 192.168.2.0 0.0.0.255 area 0

network 192.168.2.0 0.0.0.255 area 0

[Masoud Pourshabanian · Accepted solution]

Thanks Paul for mentioning that.
My terminolgy was wrong. I did mean OSPF Multipoint. I meant Ethernet provide a point to multipoint network(from a node perspective), so DR must be chosen, and it will be done automatically. I will correct my post.

Masoud

[paul driver]

Hello

The ospf network type is defined on the interface and is dependent oo the physical media type being used.

Example: interfaces
Serial interfaces = point-to-point
Ethernet – Broadcast
Loopback = Loopback

NON-Broadcast is unicast which means to get the router to establish an adjacency with another ospf router  the "neighbor"command is required and it goes through DR/BDR election

Now If you use Ethernet then this by default is a broadcast medium and as such OSPF will default to Broadcast network type thus incurring DR/BDR election process, but this can be negated and set as a point-to-point network type

int x/x ( Ethernet media)
ip ospf network point-to-point

Lastly if you advertised any loopback interfaces in OSPF with ip addressing other than a /32 then you need to define this ip ospf network point-to-point under the loopback interface as if you don’t OSPF will advertise this as a host prefix in its routing process

res

Paul