Route selection issue 1

[siki85]

I everybody,

I have the following issue about route selection. This is an extract from our router...
I have the following table:
172.16.0.0 /16 is variable subnetted, 5 subnets, 4 masks
R 172.16.1.1 /32 (120/1) via 172.16.25.2 serial 0/1/1
R 172.16.1.0 /24 (120/2) via 172.16.25.129 serial 0/1/0
R 172.16.0.0 /22 (120/1) via 172.16.25.2 serial 0/1/1
R 172.16.0.0 /17 (120/2) via 172.16.25.129 serial 0/1/0
R 0.0.0.0 /0 (120/3) via 172.16.25.2 serial 0/1/1

When I write show ip route x.x.x.x command for the IPs, it responses with routes that are confused to me....
For ip 172.16.10.1 it says that matches route 172.16.0.0 /17, but the theory says that it must match the route with the longest prefix lenght and I think it has to be 172.16.0.0 /22.
For ip 172.16.130.1 it says that matches route 0.0.0.0, what about route 172.16.0.0 /22, can it fit there ? I think so.
For ip 172.16.125.1 it says that matches the route 172.16.0.0 /17, the same think, what about 172.16.0.0 /22 ?

Please a little help because i´m confusing...

 

[unclerico]

your first route matches 172.16.0.0/17 because 172.16.0.0/22 only contains routes for 172.16.0.0 - 172.16.3.255.

your second route matches the default because of the explanation above and because 172.16.0.0/17 matches 172.16.0.0 - 172.16.127.255

your third route you can see because of the second explanation above

hope this helps

I hate all Uppercase... I don't want my groups to seem angry at me all the time! =)
- ColdFlame (vbscript forum)

 

[siki85]

NOw it´s clear to me.

thanks...

 

[Cluebird]

Give unclerico a star, then!

 

[Cluebird]

unclerico, I'll give you the star since siki85 won't.

Makes you want to not help people with questions....