[c-nsp] BGP multipath load balancing.. broken sessions upon hash change

[Chase Christian]

Correct, in order to have a "sticky" session, the device would have to keep
the TCP session state in a table somewhere (like a NAT table), which ECMP
and CEF do not do.

On Wed, Sep 2, 2015 at 2:55 PM, Łukasz Bromirski <lukasz at bromirski.net>
wrote:

> Peter,
>
> > On 02 Sep 2015, at 22:49, Peter Kranz <pkranz at unwiredltd.com> wrote:
> >
> > I’m using bgp maximum-paths and several peers announcing the same /32 to
> > create a poor man’s load balancer. This works well with up to 16 peers
> after
> > which the CEF number of buckets is exceeded.
> >
> > However, if the number of connected peers change, all sessions break,
> which
> > I would like to avoid.
>
> That’s the way CEF works - it has to rebuild the hash every
> time new nexthop appears or vanishes.
>
> This is 6500 you’ve mentioned in different post, right? What
> is the overall architecture of the thing you’re trying to
> achieve here (remote terminal access?).
>
> —
> Łukasz Bromirski
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