4: Network Layer4b-1 IP datagram format ver length 32 bits data (variable length, typically a TCP or UDP segment) 16-bit identifier Internet checksum time.
4: Network Layer4b-1 Network Layer Protocols CSIT435 Spring 2002.
Lecture 14 ICMP: Internet Control Message Protocol r used by hosts, routers, gateways to communication network-level information m error reporting: unreachable.
