[j-nsp] reliability of ping to router physical-, sub- or loopback interface

[Martin T]

Very often customers or NMS send ICMP "echo request" packages to a
router physical interface, subinterface or loopback interface and
expect ICMP "echo reply" as a response in order to test packet loss on
the connection. How reliable are Juniper routers in terms of replying
to ICMP "echo request" packages? As far as I know, ICMP traffic gets
software based handling and thus delay of the ICMP "echo reply"(or if
there is a reply sent at all) depends on the load of the CPU. Does
this depend on specific router model? Or has this more to do with
interface type? Can one prioritized/de-prioritized ICMP generation
under JUNOS?

PS many questions, but an exhaustive discussion on this topic would be nice :)


regards,
martin