Forcing a packet through an interface (OT?)

[Nate Nielsen]

Mario Lobo wrote:
> Forgive me if this is off-topic.
> 
> How could I force a packet to go out through an interface, 
> despite the default route?

What I do for testing is:

1. Assign additional local IP aliases.
2. Use IPFW or pf to forward packets that from those IPs
    through the different NICs.
3. Ping an IP online using the '-S' argument to specify
    the source as one of the IP aliases.

Cheers,
Nate