[j-nsp] BGP advertisements not making it

[Mark Tinka]

On Monday, August 02, 2010 01:10:36 pm Richard A Steenbergen 
wrote:

> Nah that's a bug, it doesn't happen on most routers. I
> couldn't even replicate it on another router with the
> same code and almost identical config talking to the
> same neighbor ASN with the same policy structure. And
> the one box where I could replicate it, I had to hard
> clear the neighbor to make the change take effect in
> either direction, a soft clear wouldn't do it. Wish my
> luck trying to get JTAC to figure THAT one out. :)

Yeah... the boxes this affects are running JUNOS 9.3R2.8. 
The ones that have 9.5R4.3 are running BGP only for v6 in 
the core, so the policies are not nearly as interesting.

Suffice it to say, we're moving everything over to 10.2 or 
later, since we need that stable NG-MVPN infrastructure. 
Let's see what happens with that :-).

> Speaking of really obscure bgp issues, have you done any
> profiling on the effects of out-delay by chance?

> It still takes ~4m30s to converge A->B, but the dynamics
> completely change. This behavior is completely
> reproducable, except if you do something which causes
> the session to reset by commit (such as changing a
> param), in which case the out-delay doesn't seem to take
> effect at all on the next re-start. But if you manually
> clear the session right afterwards, it does. :)

We haven't really played with this feature. As complex as 
our policies are, we haven't had issues with the BGP output 
queue like you're seeing. But then again, our individual 
Juniper routers don't necessarily have what I'd call "overly 
complex" policies. That honour goes to out route reflectors, 
and those jobs are Cisco 7201's. Maybe if I had Junipers for 
route reflectors, I may see that :-).

I'm guessing JTAC haven't been able to figure out why 
there's such a performance difference also, when you use 
'out-delay', and why without it, table exchange appears to 
be asynchronous.

Cheers,

Mark.
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