MPLS VPN design - RR in forwarding path?

Nick Hilliard nick at
Fri Jan 2 19:50:29 UTC 2015

On 02/01/2015 02:17, Ca By wrote:
> I agree, it makes some sense, especially if you are control plane bound.
> But, nearly all my routers run between 1% and 10% cpu.

1% and 10% on what will generally be older, slower cpus.  Modern servers
have significantly faster CPUs than any RE/RP on the market, so you will
see a benefit in terms of convergence speed by using virtualisation.

> Ymmv. I have feeling that running a bgp rr on cheap / standard / commidity
> vm is pretty exotic from a support perspective.

not really, no.  Standalone hypervisors are stable, predictable and easy to
manage. They're also commercially supported and most companies these days
have a good deal of internal experience in dealing with them.  As Mark
commented separately, you would need your head examined if you plan to
enable hypervisor clustering for this sort of thing.


> So running a bgp rr on a vm may make sense in theory, but my network
> control planes are not too busy and vm bgp is a unique/ exotic support
> model.
> Your network is probably different
>> -----
>> Mike Hammett
>> Intelligent Computing Solutions
>> ----- Original Message -----
>> From: "Jeff Tantsura" <jeff.tantsura at <javascript:;>>
>> To: "Nick Hilliard" <nick at <javascript:;>>
>> Cc: nanog at <javascript:;>
>> Sent: Thursday, January 1, 2015 7:54:32 PM
>> Subject: Re: MPLS VPN design - RR in forwarding path?
>> You don't need LDP on RR as long as clients support "not on lsp" flag
>> (different implementation have different names for it)
>> There are more and more reasons to run RR on a non router HW, there are
>> many reasons to still run commercial code base, mostly feature set and
>> resilience.
>> Regards,
>> Jeff
>>> On Jan 1, 2015, at 2:11 PM, Nick Hilliard <nick at
>> <javascript:;>> wrote:
>>>> On 01/01/2015 21:37, Baldur Norddahl wrote:
>>>> Are anyone using Bird, Quagga etc. for this?
>>> there are patches for both code-bases and some preliminary support for
>>> vpnv4 in quagga, but other than that neither currently supports either
>> ldp
>>> or the vpnv4/vpnv6 address families in the main-line code.
>>> Nick

More information about the NANOG mailing list