Routing Information Protocol (Rip); And Rip-2 - Intel ER8100STUS - Express 8100 Router Reference Manual

Routing Information Protocol (RIP)

Definition: RIP
RIP-1 and RIP-2
RIP based routing
RIP-1 and RIP-2
standards
Important differences
between RIP-1 and RIP-
2
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Routing information is exchanged by the Routing Information Protocol (RIP),
which is an Interior Gateway Protocol (IGP) based on a "Distance Vector Algo-
rithm". RIP uses the User Datagram Protocol (UDP) to exchange routing infor-
mation.
Routers inform each other about present available paths (router links to other net-
works) by RIP updates. These are sent periodically (each 30 seconds) or trig-
gered by topology changes. Each router finds the best path to any known remote
network. If a router does not receive an update from an adjacent router for 180
seconds or more, it marks the routes served by the adjacent router as unusable.
The Intel Express 8100 Router supports both RIP-1 and RIP-2. RIP-1 is the orig-
inal standard as defined by RFC 1058. RIP-2 is an update of RIP-1 and is defined
by RFC 1723. RIP-1 and RIP-2 must be considered as separate protocols.
The most important differences between RIP-1 and RIP-2 are summarized as fol-
lows:
RIP-1
Network addresses must belong to
IP address class A, B or C. Supernet-
ting is not allowed and subnetting is
only allowed if the same subnet
mask is used throughout the net-
work.
Routing updates do not contain sub-
net masks.
Routing Information Protocol (RIP)
RIP-2
Network addresses are classless—vari-
able length network masks can be used
allowing supernetting and subnetting.
Routing updates contain subnet masks.
IP Routing