BGP outgoing traffic balancing between 2 uplinks

[Sergey Popovich]

В письме от 6 декабря 2013 12:46:48 пользователь Martin Kraus написал:

> 
> I don't think there is. cisco has a bgp multipath but that basically works
> only if you have two uplinks to the same provider as it multipaths only
> routes that have nearly all the attributes the same (pref,as path,...).

Moreover, having enabled this on cisco with "bgp bestpath as-path multipath-
relax" (hidden in IOS) without completely understanding traffic paths could
lead traffic reordering and other problems, as path within AS in two upstreams
usually differ. Altough by default cisco do per flow traffic balance (src+dst 
ip...), which lowers problem.

As for function, describing "bestpath" selection algo within BIRD by 
distributing some prefix lengths across uplinks, this could improve
sharing, but this gives no real hint for data plane to reach ~50/50%.

BTW: why not use just static default routes, which is supported in BIRD
for multipath load sharing by Linux kernel? In this case all load sharing job 
will be put to ECMP implementation in Linux kernel (which is good enough
as for me).

> 
> mk

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Sergey Popovich