ip verify unicast source reachable - what does it do?

[molecul3]

Hi all,

Can anyone briefly describe to me what this line does and does not do? what sort of connections would it affect or drop? Basically i would like to know if it affects any sort of traffic e.g. smtp or ftp. excuse my ignorance but any information would be greatly appreciated.

 

[BuckWeet]

It means that traffic coming into the interface is verified against routing table. If the routing table shows a different source interface than the traffic is arriving on it drops it.. This is a anti - DoS mechanism. However... If you multiple network paths you have a good chance of asymetric routing and this will cause you many headaches.


BuckWeet

 

[eliotB]

In the Cisco docCD there are a few variations of the command.

ip verify unicast reachable-via SEC2-297

ip verify unicast reverse-path SEC2-293

Master Command List:

http://www.cisco.com/univercd/cc/td/doc/product/software/ios124/124mindx/124index.htm#LTR_I