[AusNOG] Small Pipe BNE/Agile issue

[Matthew Moyle-Croft]

James Spenceley wrote:
> In the past I've used de-aggregation to great effect to engineer more 
> traffic in dense peer meshes. It works a treat where your transit 
> provider has private peering with many of the your public peers (with 
> the peers typically local-prefing private peering higher than public).
I think this is less likely than the problem that most MLPAs introduce 
which is a longer AS-PATH.   We've had this issue recently where we see 
4 paths to one AS of equal localpref to us, but the other ASes two 
peering paths are the same or longer path so either not used or they 
bounce between the other ASes transit and peering as routes age etc.   
Not an issue for me, but for the other company it was.   We generate 
enough content in Oz to kill a lot of other people's transit!

> As for de-aggregating past a /24, I've never seen a written rule that 
> a /24 is ok to distribute and a /25 isn't, globally nothing works past 
> a /24, that's generally accepted but peering is a bi-lateral 
> relationship (even with an MLPA). 
Hold on a tick here.   How so?   With an MLPA (eg PIPE/WAIX/etc) I have 
no direct relationship with the other party - only with the MLPA IX.  If 
I want to mess with routing it affects all peers at that MLPA.   For 
instance, I have NO idea how, except informally to contact almost anyone 
else's NOC at PIPE.   Whereas for all my bilaterals I have a lovely list 
of phone numbers/email addresses/IM/etc if I have an issue.   See 
recently with PowerTel's TNZ inspired depeering at PIPE but not WAIX - 
routing went all via WAIX.  In order to get them to fix it I had to 
discover their NOC's details through AUSNOG mailing list (thanks to the 
people who sent me their details).  If I had been doing bilaterals with 
them then I'd have had the details and also be able to kill routes 
specifically to them in Perth without affecting the other people on WAIX.

> If using /25 or greater has a required effect there is no reason not 
> to use it but likewise no requirement to accept it.
That's a bit out of kilter with your previous statement.  

I could ignore longer than /24s - but as you've said above at the MLPAs 
a lot of people use deaggregation to do TE.   So, unless the MLPA IX 
Route Server blocks it, I'm left with little option but accept them or 
have people complain that somehow my routing skills are poor (something 
that doesn't sit well).

MMC

-- 
Matthew Moyle-Croft - Internode/Agile - Networks
Level 4, 150 Grenfell Street, Adelaide, SA 5000 Australia
Email: mmc at internode.com.au  Web: http://www.on.net