On Jun 11, 2010, at 5:50 PM, Paul Jakma wrote: >> A1) A "node" is either a host or a router. >> >> A2) A "router" is any device that forwards packets at the >> Network Layer (e.g. IPv4, IPv6) of the Internet Architecture. >> >> A3) A "host" is a device that can send/receive packets >> to/from the network, but does not forward packets. >> >> A4) A "bridge" is a device that forwards packets at the >> Link Layer (e.g. Ethernet) of the Internet Architecture. >> An Ethernet switch or Ethernet hub are examples of bridges. > > I agree more or less with the above, though there are exceptions. E.g. > obviously there may be nodes which are both hosts and routers; also there may > be hosts which perform logical routing functions, without being involved in > forwarding.
I view these terms as being mostly meaningful with respect to a conversation in progress. A system that forwards IP datagrams at the IP layer is an IP router; an IP router, unless completely static in its configuration, also exchanges datagrams with other routers in routing protocols, and is with respect to those protocols a host (it originates and receives datagrams directed to itself). Some IP routers contain built-in bridging technology, either software or hardware. _______________________________________________ rrg mailing list [email protected] http://www.irtf.org/mailman/listinfo/rrg
