Chapter 3 Rip Configuration; Rip Overview; Rip Working Mechanism - H3C S7500 Series Operation Manual

Operation Manual – Routing Protocol
H3C S7500 Series Ethernet Switches

Chapter 3 RIP Configuration

When configuring RIP, go to these sections for information you are interested in:

RIP Overview

RIP Configuration Task List
Displaying and Maintaining RIP Configuration
RIP Configuration Example
Troubleshooting RIP Configuration
3.1 RIP Overview
Routing Information Protocol (RIP) is a simple Interior Gateway Protocol (IGP), mainly
used in small-sized networks.

3.1.1 RIP Working Mechanism

I. Basic concept of RIP
RIP is a distance-vector (D-V) algorithm-based protocol. It exchanges routing
information via UDP packets.
RIP uses hop count (also called routing cost) to measure the distance to a destination
address. In RIP, the hop count from a router to its directly connected network is 0, and
that to a network which can be reached through another router is 1, and so on. To limit
convergence time, RIP prescribes that the cost is an integer ranging from 0 and 15. A
cost value of 16 (or bigger) is considered infinite, which means the destination
network or host is unreachable.
To improve performance and avoid routing loop, RIP supports split horizon. Besides,
RIP can import routes from other routing protocols.
II. RIP routing table
Each router running RIP manages a routing table, which contains routing entries to all
the reachable destinations. Each routing entry contains:
Destination address: IP address of a host or network.
Next hop address: IP address of an interface on the adjacent router that IP
packets should pass through to reach the destination.
Interface: Interface on this router, through which IP packets should be forwarded
to reach the destination.
Cost: Cost from the local router to the destination.
Routing time: Time elapsed since the routing entry was last updated. The time is
reset to 0 whenever the routing entry is updated.
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Chapter 3 RIP Configuration