[c-nsp] Opinions about ICMP Destination Unreachable

[Dino Farinacci]

I am just wondering how many people have ICMP Destination Unreachables  
disabled on their core routers. Could an CPE router, which may  
encapsulate data, be able to depend on ICMP Unreachables to be sent to  
it?

I know there are many cases where router implementations default it to  
off (to not send ICMP DUs), but wondering who leaves it this way or  
turns them on? Of when it defaults to on, who explicitly turns them off.

Thanks in advance,
Dino