[c-nsp] How to force ICMP packet out from an Ethernet interface?

[Min Qiu]

Hi,

I need to test a p2p ethernet.  I loop one side and try
to ping from another side.  It appears to me the ICMP
packet does not touch the interface at all by doing show
interface command, when I ping local IP address.  Anyway 
to do that?

Thanks a lot,

Min