"port unreachable"are often related to a single connection and therefore include original IP header and 64 bits of transport header. However, older versions of TCP/IP don't work that way
"ICMP redirect"messages can be used to take over a route to a server or client, which is a Bad Thing.
stalin# mail email@example.com < secretfile may be sent to firstname.lastname@example.org in Czechia!
(file handle, IP, user id, op, data)-tuples for transactions
Example: become root@euler power-cycle euler snoop net for root file handle for root file system now you can send some NFS lookups and getattrs (with eulers source address) to get file handles for /etc/passwd and /etc/group write your own copies, with your data login or su Do not try this at home, it's illegal!