'Jeremy Chadwick' wrote:
That's an excellent question -- and one I've always wondered myself.
This is purely speculative, but I believe outbound ICMP (e.g. sent from the router to whatever src solicited it) is what's de-prioritised.
Someone more familiar with Cisco and Juniper equipment might know for certain.
Usually packets destined to the control-plane of the system are prioritized based on criteria. It is better to let routing control protocols (e.g. ospf, bgp, isis) through first than someone pinging or running a traceroute. Packets *through* the router take the normal forwarding path and are not affected by this system. There may be system defaults based on hardware/software, but Cisco has CoPP and I believe Juniper uses a firewall on the lo0 interface (been a while since I touched one) for user-defined rules. -- Devon