[c-nsp] Multilink PPP Over Multiple LNS(es)

[Garry]

On 17.11.2010 16:17, Dominic Ogbonna wrote:
> (a.) Let's say you have two LNS(es): Lns-1 and Lns-2
> (b.) Let's say each builds its own transport L2TP tunnel back to the LAC(s),
> perhaps via redundant circuits
> (c.) Let's say the LAC(s) religiously round-robin between the two LNS(es)
>
> In the above scenario, what would be the best practice for supporting
> Multilink PPPOE / Bonded ADSL on the LNS?
>
> I ask because, if you enable multi-link on both LNS(es), you obviously end
> up with multilink bundles where the L2TP session is split between two L2TP
> tunnels - one link authenticating to one LNS/tunnel, the other
> authenticating  to a different LNS/tunnel, leading to all kinds of routing
> and network weirdness, especially when one of the multilink member-links
> drops. 
>
> For LNS box, we are talking two Cisco 7206 with NPE-G2, so Multi-Chassis LNS
> is not an option.
SBGP will work out fine ... had it running with four routers (2 7206, 2
3825) without any problem ... upon incoming connection, the LNS will
check with the other SBGP boxes to see whether it's an additional
connection ... if not, it will just keep the connection with itself,
otherwise it will forward the connection via L2TP to the LNS that
already has one or multiple connections for that remote site ...

-garry