[j-nsp] Multipath BGP issue

[Paul Stewart]

Felix... thank you VERY much.  You have answered something that I completely
forgot about and should have remembered.

This is the first transit customer we've had that was homed off the same
equipment on both BGP sessions (all of the others always hit separate
equipment for physical redundancy) ... was bugging me why we didn't run
across this before ;)

JTAC has had a "high" ticket on this for 24 hours now and you answered what
I needed to know inside of roughly 30 minutes.

Thank you again,

Paul


-----Original Message-----
From: Felix Schueren [mailto:felix.schueren at hosteurope.de] 
Sent: Thursday, June 02, 2011 9:31 AM
To: juniper-nsp at puck.nether.net
Cc: paul at paulstewart.org
Subject: Re: [j-nsp] Multipath BGP issue

Paul,

by default JUNOS will do per-prefix balancing with multipath. Did you 
configure "load-balance per-packet" (which actually is per flow and 
named this for historical reasons) on forwarding table export?

For the load balancing to put multiple paths to the same target into the 
forwarding table, you'll need (besides identical bgp attributes up to 
the obscure tiebreakers):
top
set routing-options forwarding-table export <name-of-policy>

The simplest version of <name-of-policy> is:
top
edit policy-options policy-statement <name-of-policy>
set then load-balance per-packet


 >
 > Is there a legit issue here somewhere?  JTAC seemed to indicate they 
wanted
 > to further investigate my import policy but I don't see anything wrong
 > here.. ?
 >
 >
I think you are just lacking the load-balance per-packet magic towards 
the forwarding engine.

Does this help?

Kind regards,

Felix


-- 
Felix Schüren
Head of Network

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