OSPF Network Command

dppagc

int fa0/0
ip add 192.168.1.1 255.255.255.0
no shut

What is the difference between

router ospf 1
192.168.1.1 0.0.0.255 area 0

AND

router ospf 1
192.168.1.1 0.0.0.0 area 0

They will both advertise the route right?

networker050184

The network statement doesn't tell the router what to advertise. It tells the router which interface to participate in the process. So if an interface IP falls within the range of the network command it participates in that area and advertises the attached network and mask.

So, in your case for the first one any interface with IP 192.168.1.1-255 will take part in the OSPF process. The second one only an interface with the IP 192.168.1.1 exactly will participate in the process. Again, what get advertised depends on the mask on the actual interface.