Information Technology Reference
In-Depth Information
Study Guide
RIPv1: Distance Vector, Classful Routing Protocol
RIPv1 is a distance vector routing protocol for IPv4. RIPv1 is also a classful routing protocol. In the
following sections, you will focus on the basic RIP concepts.
RIP Concepts Exercise
Background and Perspective
RIP is the oldest of the
distance vector
routing protocols. However, RIP is not a protocol “on the way
out.” In fact, an IPv6 form of RIP called
RIPng
(next generation) is now available.
RIP Historical Impact
RIP evolved from an earlier protocol developed at Xerox, called
Gateway Information Protocol
(
GWINFO
). It later gained popularity because it was implemented in the
Berkeley Software
Distribution
(
BSD
) as a daemon named
routed
. Various other vendors made their own, slightly differ-
ent implementations of RIP. Recognizing the need for standardization of the protocol, Charles Hedrick
wrote RFC
1058
in 1988, in which he documented the existing protocol and specified some improve-
ments. Since then, RIP has been improved with
RIPv2
in 1994 and with
RIPng
in 1997.
RIP Characteristics
As discussed in Chapter 4, “Distance Vector Routing Protocols,” RIP has the following key characteristics:
It is a
distance vector
routing protocol.
■
It uses
hop count
as its only metric for path selection.
■
Advertised routes with
hop counts
greater than
15
are unreachable.
■
Messages are broadcast every
30
seconds.
■
Figure 5-1 shows an encapsulated RIPv1. Fill in the missing field content.
