Explaining and Configuring the RIPv2 Routing Protocol

RIP and RIPv2

RIP stands for Routing Information Protocol. It is a distance-vector protocol based on hop count. Although RIPv1 and RIPv2 are similar, RIPv2 addresses some of the deficiencies of RIP by providing better security, supporting multicast traffic, and manual route summarization. In this blog, I will focus on RIPv2 as it’s the newest version.

In example 1, when a packet is sent from R1 to R2, it is considered a single hop. RIP will try to use the lowest hop count to calculate its route. When R1 wants to send a packet to R3, there are two routes. RIP uses an algorithm to detect which route has the lowest hop count. If route 1 has two-hop counts and route 2 has 3 hop counts, the algorithm will pick route 1 over route 2.

Example 1.

How RIP updates the Routing Table

Update timer: 30 seconds – All routers configured with RIP sends updates every 30 seconds

Invalid Timer: 180 seconds – If router is disconnected from network, neighbour router waits 180 seconds to hear an update. If no update, route is marked as unreachable

Flush Timer: 240 seconds – if router does no send an update for 4 minutes, the neighbour router will completely remove the route from the routing table

Limitations:

  • RIP is only based on hop count, not bandwidth. Therefore, if route 1 is only a 100kbps link and route 2 is a 100mbps link then route 2 will obviously be faster even if there are more hops to get the packet to R3.
  • Has an administrative Distance is 120. The lower the administrative distance for a routing protocol, the more reliable it is. RIP has the highest AD value.
  • RIP broadcasts updates to the entire network thus creating lots of traffic
  • RIP supports a maximum of 15 hops
  • Slow convergence (when one link goes down, it will be a long time to find an alternate route)

Configuring RIPv2

RIPv2 is extremely easy to configure. That is one of the main advantages of RIP. There is no complexity to it, therefore it’s a good beginner routing protocol to learn. This is a simple RIPv2 configuration with three routes and two networks.

COMMANDS:

#R1
en
conf t

int g0/0
ip address 10.0.0.1 255.255.255.0
no shut

router rip
ver 2
network 10.0.0.0
network 192.168.0.0
#R2
en
conf t

int g0/0
ip address 10.0.0.2 255.255.255.0
no shut

int g1/0
ip address 192.168.0.1 255.255.255.0
no shut

router rip
ver 2
network 10.0.0.0
network 192.168.0.0
#R3
en
conf t

int g0/0
ip address 192.168.0.2 255.255.255.0
no shut

router rip
ver 2
network 10.0.0.0
network 192.168.0.0

After it has been configured, make sure to try pinging the G0/0 network on R3 from R1 to confirm it’s working

And then confirm the routes by entering “show ip route” on R1 and R3

The configuration looks right

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