[c-nsp] Multiple Ethernet links for redundancy

[Brett Frankenberger]

On Sat, Nov 08, 2008 at 04:26:09AM +0200, Mario Spinthiras wrote:
> Most beneficial is to port-channel the interfaces. This is clever in many
> ways. Handling the interface redundancy any other way complicates things
> IMHO. With a port-channel interface you have more bandwidth and redundancy.

And you also have exposure to any failure that puts one of the links
into a DOWN state on end of the link but not on the other and any
failure that prevents traffic from flowing over a link but doesn't put
the interfaces into a DOWN state.

On the other hand, having two Layer 3 links and running a routing
protocol protects against most such failures -- if the OSPF hellos
aren't being received bidirectionally, the link won't get used.

     -- Brett