The route should be configured to achieve the following purposes: 1) All routers run the RIP
routing protocol; 2) RouterB and RouterC can learn the network segment routes advertised;
3) RouterE can learn the routes of the 192.168.12.0/24 network segment.
Detailed configuration of devices
In this example, to achieve the above purposes, RouterA and RouterD must have split
horizon disabled. Otherwise, RouterA will not notify the routes advertised by RouterB to
RouterC. Neither will RouterD advertise the 192.168.12.0 network segment to RouterE.
Detailed configurations of each device are listed as follows.
Configuration of Device A:
# Configuring Ethernet port
interface FastEthernet0/0
ip address 192.168.12.1 255.255.255.0
# Configure the WAN port
interface Serial1/0
ip address 192.168.123.1 255.255.255.0
encapsulation frame-relay
no ip split-horizon
# Configuring RIP route protocol
router rip
version 2
network 192.168.12.0
network 192.168.123.0