unknown IP prefix

[rickr4433]

If a router gets a packet that is not covered by any prefixes in its routing table, what should it do with the packet?

 

[bcastner]

It tosses it out.

 

[bcastner]

That was too quick an answer.

If you look at the routing table there is always a Gateway of last resort. (look for a 0.0.0.0 entry). It throws it at that Gateway, which then tosses it out.

 

[Morsing]

???!?

If it's not covered by any entry (even a default one) it will drop the packet an send an ICMP network unreacheable to the source host.

Cheers

Henrik Morsing
Certified AIX 4.3 Systems Administration
& p690 Technical Support