[TUHS] VRFs (was Re: moving directories in svr2)

Derek Fawcus dfawcus+lists-tuhs at employees.org
Wed Jan 5 01:40:17 AEST 2022


On Mon, Jan 03, 2022 at 03:23:54PM -0500, Theodore Ts'o wrote:
> 
> Well, take a look at the ip-route man page.  The BSD route command
> assumes fundamentally there is a single routing table that you can
> update.  In Linux, there are multiple routing tables --- to support
> NAT, VRF (virtual routing and forwarding), etc.

Well, I never found the multiple-table thing to be that much like
VRF stuff which one would find one cisco/juniper/etc, I found it
more like a PBR scheme...

In terms of doing stuff like VRFs, I generally just configure
multiple network namespaces, and ignore the multiple tables.

That said, there is now another explicit mechanism for VRFs in Linux,
based in part off VLANs, and special interfaces.  Maybe it also uses
the multiple tables stuff?

So is that 2.5 to 3 mechanisms for achieving VRFs, and/or other weird
and wonderful networking games?

DF


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