OSPF wildcard mask statement

brewoz40

Trying to figure out what the best wildcard mask command would be for route sumarization as well as best practice in real world for a router that has an interface with 10.10.0.0 /22 and 2 interfaces with 10.10.52.0 /30. Would this require 2 commands:
network 10.10.0.0 0.0.0.3.0 area 1
network 10.10.52.0 0.0.0.3 area 1

or since all interfaces are in the same area, use a single statement such as:
0.0.0.0 255.255.255.255 area 1

Thanks!

hexem

One of you're network statement's are incorrect.

network 10.10.0.0 0.0.0.3.0 area 1

need's to be

network 10.10.0.0 0.0.0.3.255 area 1


in regard's to you're question both will work, being more specific with wildcard mask's is down to you and what other interfaces you have or may not want participating in a paticular area.

if you had multiple interface's in differn't area's it wouldn't work.

Forsaken_GA

ospf network statements do not create routes or summarizations. The only thing they do is tell OSPF which interfaces are going to participate in the OSPF process.

best practice for OSPF is to set all interfaces to passive by default, then identify which interfaces you want ospf running on, identifying those interfaces explicitly with a network statement, and then turning passive interface off for that interface. This way there will be no accidental neighbor relationships established.

the area # range command is what you use to create your summary routes

brewoz40

Thanks for the correction in the statement and the replies. Sorry, what i meant with route summariztion is the best route summarization statement for the network statement, especailly if have multiple area's. Would you say it's best pratice if all interfaces will be in the same area to use the single statement, or is it really a personal preference thing?

*BB*

hexem wrote: »

need's to be

network 10.10.0.0 0.0.0.3.255 area 1

you are really gonna throw him for a loop with that wildcard mask

networker050184

brewoz40 wrote: »

Thanks for the correction in the statement and the replies. Sorry, what i meant with route summariztion is the best route summarization statement for the network statement, especailly if have multiple area's. Would you say it's best pratice if all interfaces will be in the same area to use the single statement, or is it really a personal preference thing?

I think its best practice to get them as specific as possible. Personally I use a 0.0.0.0 mask for the specific IP. I like the interface commands too, but I've never used them in production.

Forsaken_GA

brewoz40 wrote: »

Thanks for the correction in the statement and the replies. Sorry, what i meant with route summariztion is the best route summarization statement for the network statement, especailly if have multiple area's. Would you say it's best pratice if all interfaces will be in the same area to use the single statement, or is it really a personal preference thing?

You never know if you'll need to change an interface to another area at some point, so it's generally a bad idea to issue a blanket statement that will cover more than one interface. Best practice is always going to be to do something on purpose without invoking the Law of Unintended Consequences. I personally don't bother with network statements, I enable ospf on the interface directly through interface configuration mode. If I need to include a route for an interface that doesn't need to participate in OSPF directly, I'll redistribute the connected interface into OSPF

But for CCNA purposes, you'll probably be best served by using a network statement with a proper inverse mask that will only match the desired interface

chmorin

*BB* wrote: »

you are really gonna throw him for a loop with that wildcard mask

At that point the cisco IOS would be kind enough to say:

"HEY! Not quite.... try again."