ICMP Destination Unreachable replies on cisco routers
The book i'm reading says that if you have a unreachable destination you will recieve a "U", network/subnet an "N" and can't fragment a "U". I can't seem to get any of these in a reply. Am I doing something wrong? I don't think i've ever seen them in a reply on a router, but I have seen destination unreachable messages on windows/linux boxes.