[Day 7] 3. RIP Configuration

On Router A:


A(config)# router rip
A(config-router)# network 172.16.0.0
A(config-router)# network 202.208.220.0

On Router B:


B(config)# router rip
B(config-router)# network 172.16.0.0

Configuration:
Both routers are configured to use RIP to advertise their respective networks.
Advertisement:
- Router A advertises the
```
172.16.10.0/24
```
  network to Router B.
- Router B advertises the
```
172.16.30.0/24
```
  network to Router A.
Data Packets:
The RIP control packet contains network information, including network IDs and hop counts. When Router B receives this packet from Router A, it updates its routing table and learns the next hop (Router A's IP address) to reach Router A’s networks.
Routing Tables:
- Router A learns about
```
172.16.30.0/24
```
  through Router B.
- Router B learns about
```
172.16.10.0/24
```
  through Router A.
Periodic Updates:
RIP sends updates every 30 seconds to keep the routing tables current and up-to-date.

RIP can be configured to stop sending updates on certain interfaces using the

passive-interface

command. This is useful when we want to receive RIP updates but prevent sending updates on an interface.

Example Configuration:
Suppose Router A is connected to a network

202.208.220.0

and Router A doesn't want to send RIP updates on the interface connected to this network but still wants to receive updates.


A(config)# router rip
A(config-router)# passive-interface g0/0
A(config-router)# network 202.208.220.0
A(config-router)# passive-interface g0/2

This configuration tells Router A not to send RIP updates on interface

g0/0

but still advertise the

202.208.220.0

network. It will also stop sending RIP updates out of interface

g0/2

The
network
command is essential to enable RIP on an interface, even when
```
passive-interface
```
is used to stop sending updates on that interface.
The
passive-interface
command does not block data traffic. Data packets will still pass through the interface as usual, but RIP updates will not be sent out of the interface.
When
passive-interface
is used, RIP updates will not be passed to another router, but the router will still accept updates from the other router.

Network Setup:
Router A is connected to Router B, forming a simple two-router setup:
```
A <--> B
```
.

Configuration on Router A:

Apply
```
passive-interface
```
to the interface that connects to Router B. This will prevent Router A from sending RIP updates to Router B.


A(config)# router rip
A(config-router)# passive-interface g0/0
A(config-router)# network 172.16.10.0

Explanation:
- Router A will not send RIP updates out of
```
g0/0
```
  (interface connected to Router B) but will still receive RIP updates from Router B on that interface.
- Router B will continue to send and receive RIP updates normally.