Daily Archives: April 25, 2013

catenet… rfc 791 IP…

                           INTERNET PROTOCOL

                         DARPA INTERNET PROGRAM
                         PROTOCOL SPECIFICATION

                            1.  INTRODUCTION

1.1.  Motivation

  The Internet Protocol is designed for use in interconnected systems of
  packet-switched computer communication networks.  Such a system has
  been called a "catenet" [1].  The internet protocol provides for
  transmitting blocks of data called datagrams from sources to
  destinations, where sources and destinations are hosts identified by
  fixed length addresses.  The internet protocol also provides for
  fragmentation and reassembly of long datagrams, if necessary, for
  transmission through "small packet" networks.

"Catenet is an obsolete term for a system of packet-switched communication 
networks interconnected via gateways."

1.1.d Explain IP operations

doyle, from routing tcpip vol 1

the router will send three packets with the TTL set to one; the first router will decrement it to zero, drop the packets, and send back error messages to the source. By reading the source address of the error messages, the first router on the path is now known. The next three packets will be
sent with a TTL of two. The first router decrements to one, the second to zero, and an error
message is received from the second router. The third set has a TTL of three, and so forth,
until the destination is found. All routers along the network path will have identified
themselves.