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Old 10th November 2010
SlyM SlyM is offline
Port Guard
 
Join Date: Nov 2010
Posts: 21
Default Now with 2 NICs installed...

Now I'd like to understand with 2 NICs installed for egress traffic, 1 for each ISP connection. With multipath default routes to each ISP's respective default gateway next hops, why is it that the box only uses the secondary ISPs connection exclusively?

If I issue a $ping 8.8.8.8

The ping times are appropriate for the usual latency of the secondary connection. This is confirmed by issuing a $traceroute 8.8.8.8 and watching traffic go down that route.

If I issue a $ping -I {IP of the primary connection} 8.8.8.8

The pings work, and have the usual latency that can be expected on that line. This can also be confirmed by issuing a $traceroute -s {IP of the primary connection} 8.8.8.8 and watching the traffic go down the primary line this time.

Then to really make matters worse, if I issue a $ping -I {IP of the secondary connection} 8.8.8.8
This fails....as does $traceroute -s {IP of secondary connection} 8.8.8.8

Why? It should work if it works when not specifying any address. And when not specifying any address, shouldn't it pick a connection to use at random or using a round-robin method with multipath routing enabled, or am I misunderstanding something again?
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