[c-nsp] [j-nsp] L3VPN/RR/PE on Same router

[Mark Tinka]

On 17/Aug/18 10:56, Robert Raszuk wrote:

> Hey Mark,
>
> It has been a while ....

It has, mate. Good to see you in these parts again :-)...


>
> Out of pure curiosity how are you setting up different BGP sessions to
> the same RR ? 
>
> I think what Adam is proposing is real TCP session isolation, what you
> may be doing is just same single TCP session, but different SAFIs
> which is not the same.

You're right; I should have clarified that better - we are, indeed,
running one TCP session with multiple SAFI's.

The only uniqueness between BGP sessions at a TCP level would be by IP
protocol, i.e., IPv4 and IPv6. But even within IPv6, we carry multiple
SAFI's across a single TCP session.


>
> Sure you can configure parallel iBGP sessions on the TCP level say
> between different loopback addresses to the same RR, but what would
> that really buy you ? You could even be more brave and use BGP
> multisession code path (if happens to be even supported by your
> vendor) which in most implementations I have seen is full of holes
> like swiss cheese but is this what you are doing ?

I'm not that brave :-).

But to your point, the complete hardware and Layer 4 separation of BGP
sessions, perhaps going one step further and having separate planes for
different SAFI's, is overkill, IMHO. But that's just me.

As I mentioned before, we've had our setup since 2014. With the
exception of x86 hardware being more sensitive to temperature
situations, causing related failures, we haven't had any issues at all.


> PS.  Have not been reading -nsp aliases for a while, but now I see
> that I missed a lot !  Btw do we really need per vendor aliases here ?
> Wouldn't it be much easier to just have single nsp list ? After all we
> all most likely have all of the vendors in our networks (including
> Nokia !) and we are all likely reading all the lists :) Or maybe there
> is one already ?

There isn't one to rule them all, AFAIK. In fact, Arista-NSP went live
just yesterday, if I'm not mistaken :-).

I think there is value in having separate lists for the different
vendors. I wouldn't say all network operators have each of them to make
one list the ideal. Besides, there are a lot of things I have zero
interest in on one list that I wish I could filter out (SRX on j-nsp,
ASA on c-nsp, as examples). You can imagine what that'd be like on a
single list :-).

Mark.