Things that a router needs to worry about a Integrity of an incoming packet Checksum for the header a Source address spoofing(limited) a Receiving: queueing, scheduling, detunneling, etc o Dropping or forwarding a Dropping (TTL, broadcasting, congestion, and the integrity issues)and feedback n Forwarding: destination address (and perhaps source addresses and interface), and Tos 口 Forwarding a Fragmentation, tunneling, source address and port translationThings that a router needs to worry about 4  Integrity of an incoming packet:  Checksum for the header  Source address spoofing (limited)  Receiving: queueing, scheduling, detunneling, etc  Dropping or forwarding  Dropping (TTL, broadcasting, congestion, and the integrity issues) and feedback  Forwarding: destination address (and perhaps source addresses and interface), and TOS.  Forwarding  Fragmentation, tunneling, source address and port translation