show ip route longer -prefix

[sarahr202]

Hi everybody.

R2#show ip route 10.0.0.0 255.0.0.0 longer-prefix

     10.0.0.0/8 is variably subnetted, 3 subnets, 3 masks
S       10.10.0.0/16 is directly connected, FastEthernet0/0
S       10.10.10.0/24 is directly connected, FastEthernet0/0
S       10.0.0.0/8 is directly connected, FastEthernet0/0

Above, all the subnets that falls with in address space 10.0.0.0/8 and present in the routing table.

What if we don't specify the subnet mask i.e:

R2# show ip route 10.0.0.0 longer-prefix

Will router assume default mask of 255.0.0.0 and shows  all the subnets present in the routing table which fall with in address space 10.0.0.0/8 ?

I issued the command " show ip route 10.0.0.0 longer-prefix " as shown below:

R2#show ip route 10.0.0.0 longer-prefix

     10.0.0.0/8 is variably subnetted, 3 subnets, 3 masks
S       10.10.0.0/16 is directly connected, FastEthernet0/0
S       10.10.10.0/24 is directly connected, FastEthernet0/0
S       10.0.0.0/8 is directly connected, FastEthernet0/0

Looks like R2 assume default mask of 255.255.0.0.

I just want to clarify it.

Thanks and have a great weekend.

[cadet alain · Accepted solution]

Hi,

both outputs are the same and it looks like when specifying no mask it assumes the classful mask indeed.

Regards.

Alain

Don't forget to rate helpful posts.

[sarahr202]

Thanks Alain.

Have A nice weekend