Technical Tip: Configuring RIPv2 with MD5 authentication

Description

This article describes how to configure, validate and debug RIPv2 using MD5 authentication.

Scope

FortiGate, RIP.

Solution

Configure the keychain entry with the matching Key ID, define its password string, and apply the configuration to the designated interface.

FortiGate-1 example configuration:

1. Configuring a Key Chain:

config router key-chain
    edit "fgt"
        config key
            edit "1"
                set accept-lifetime 00:00:00 01 01 2026 infinite
                set send-lifetime 00:00:00 01 01 2026 infinite
                set key-string TestKeyChain123
            next
        end
    next
end

2. Configuring RIPv2:

In the following:

• 'set prefix 10.0.3.0 255.255.255.252' is the External Interface Network.

• 'set prefix 192.168.200.0 255.255.255.0' is the LAN network.

config router rip
    config network
        edit 1
            set prefix 10.0.3.0 255.255.255.252 
        next
        edit 2
            set prefix 192.168.200.0 255.255.255.0
        next
    end
    config interface
        edit <External_Interface>
            set auth-keychain "fgt"
            set auth-mode md5
            set receive-version 2
            set send-version 2
        next
    end
end

Note:

For FortiGate-2, it is necessary to update only the LAN network entries under 'config network'.


Validation and Debugging:

1. Verify route entry installation in the main routing table:

get router info routing-table rip

2. Inspect the local routing protocol database:

get router info rip database

3. Debug RIP:

diagnose debug enable
diagnose ip router rip all enable