ivan on ospf network statements…

ivan p. says:

http://blog.ioshints.info/2007/07/be-smart-when-using-ospf-network.html

In my network implementations, I use the network statements in three different ways:

  • If I have to assign a specific interface into an area, I would always use network x.y.z.w 0.0.0.0 area n;
  • If the area address ranges are nicely assigned (which also helps immensely when you have to start summarizing), you can use a single network statement to cover the whole area. If, for example, area 3 has address range 10.1.16.0/20, use network 10.1.16.0 0.0.15.255 area 3;
  • If the router has all interfaces in a single area, I would almost always use network 0.0.0.0 255.255.255.255 area area-id (unless there is an extremely good reason that some interfaces should not be seen by the OSPF process).

now this is interesting… i was watching a kevin wallace video pbr in ospf here:

http://www.youtube.com/watch?v=JfWe-VpDdec

and at 8mins 25secs he uses this command…

network 0.0.0.0 0.0.0.0 area 0

and it threw me… i often use network 0.0.0.0 255.255.255.255 area 0 in labs because A) it’s now a  habit i picked up from doing arden packeer labs months ago and B) it’s fast and furious while i’m experimenting… i would never do this in production, of course… the more specific, the better…

so why would kevin wallace use 0.0.0.0 0.0.0.0 area 0? WTF

to save himself some key strokes… see below:

dsw1(config)#router ospf 100
dsw1(config-router)#netw 0.0.0.0 0.0.0.0 area 0
dsw1(config-router)#do sh run | b router ospf 100
router ospf 100
log-adjacency-changes
network 0.0.0.0 255.255.255.255 area 0

ios to the rescue… however i will continue to use the all 1’s after the all 0’s because i’m insane and i don’t like shit like that…