In the FRRouting routing protocol debugging blog entry, there is a debugging approach explained how to get routing protocol debugging messages in FRRouting. This kind of debugging works for all versions of FRRouting, WHEN you have the possibility to leave the vtysh shell and use a regular system shell, like f.e. bash or zsh. If there is no possibility to leave the vtysh then there is no way getting routing protocol debug messages using FRRouting.

But, since FRRouting version 9 it is possible to get the routing debugging protocol messages using the terminal monitor command. This works without leaving the vtysh. It works the same way as it works in Cisco IOS products.

If using IOS, NX-OS or IOS-XR network operating system, the debug routine works simply, like in shown example below. Exactly 2 commands are needed to use interactive protocol debugging while being in need of troubleshoot in some situation:

configure terminal
 logging console
end

Enable specific IOS protocol debugging option:

terminal monitor
debug ip ospf adj

Using FRRouting, the routing debugging routine will work the same. vtysh has now the option to interactive write protocol debug to the vtysh prompt.

This article is a simple demonstration using the RIPng, OSPF6 and IS-IS routing protocol debugging, to show the different debug options in action.

Enable the routing protocol debugging in the FRR vtysh. First example below is showing a RIPNG routing protocol debug.

This is working using since:

Hello, this is FRRouting (version 9.0.1).
Copyright 1996-2005 Kunihiro Ishiguro, et al.

debug ripng

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