Path Manipulation

[jinkazama_2]

Hi guys,

Just getting back into my studies, I have a hypothetical question. Suppose I have a router with 2 x FE ports. I want traffic over port FE0 to be captured on port FE1. What would be the best way for me to do this? SPAN, or can this be completed using Route Maps?

Thanks

Omid

[mheusinger]

Hello Omid,

a router will not forward a unicast packet to two ports. The simplest approach to packet capturing would be a hub. Or you use a LAN switch with SPAN capabilities.

Depending on the informations you are interested in even a debug in the router might allow you to monitor, what you are interested in. Just keep in mind that "debug" is a CPU intense task and might even crash a router.

Regards, Martin

[jinkazama_2]

Hi Martin,

Basically I wish to capture these packets on a packet analysing tool. My router a 2800 has two FEports. FE0 is where tha packets are coming in. I want these to be router normally, but I also want them to goto FE01. I could stick a hub on FE0, but was wondering if there was anyway to get around this, similar to how SPAN works on a switch? I know SPAN can mirror traffic on the Etherswitch HWIC, but didnt know if it could do the same on the onboard interfaces?

Thanks for the help

Omid

[mheusinger]

Hello Omid,

I know what you are looking for, but to my knowledge there is no such feature in a router. Sorry. This is, why I wrote about the treatment of unicast packets in a router.

The behaviour you would like to see would defeat the idea of IP unicast traffic. In a switch this behaviour is part of normal operation - unknown unicast frames are flooded within a VLAN.

Regards, Martin