On 5/6/15 15:56, Randy Bush wrote:
a fellow researcher wants
> to make the case that in some scenarios it is very important for a > network operator to be able to specify that traffic should *not* > traverse a certain switch/link/group of switches/group of links > (that's true right?). Could you give some examples? Perhaps point > me to relevant references?
if so, why? security? congestion? other? but is it common? and, if so, how do you do it?
My experience has been with MPLS overlays. Availability: During maintenance windows, moving high-value traffic away from potential outages while keeping the tunnels full of BE; manually manipulating MPLS tunnel affinities (though this could be automated fairly easily). Congestion: Whenever traffic load spikes past a threshold; diffserv-aware TE to prevent certain classes of traffic from routing over links with limited bandwidth, handled automatically via auto-bw. Preventing non-optimal tunnel paths. No transoceanic trombones, please; MPLS link affinities designed into the network. -Scott