You really need to use a dynamic routing protocol when clustering and BGP is the only support one WITHIN L2TPNS that it supports.

Others use L2TPNS clusters but then might choose to use Quagga to use some other routing protocol, and some also feel Quagga's routing implementations, including BGP is better than the one built into L2TPNS. Quagga works by detecting the systems local IP cache table to determine what to advertise via whatever routing protocol.

Interesting, I'll read about Quagga.

The reason you need a dynamic routing protocol between your L2TPNS cluster and its gateway is multipathing. Sure, you could statically route user ranges to the cluster on your routed with equal costed routes, but if one of the nodes every drops out you'll be dropping every X packets to the cluster. Hence the reason for BGP, because each node in the clusters advertises the same IP ranges that every other node in the cluster advertises (apart from the master when "cluster_master_min_adv" is reached at which stage the master doesn't advertise anything via BGP APART FROM any throttled or walled garden sessions. Keep this well in mind when doing a cluster setup, if your doing a lot of throttle or walled garden session the master is the only one that takes care of this traffic (due to IPTABLES traversal)).

Fortunately, we're not using walled/garden sessions at this time.

There's no real great detailed documentation on BGP or clustering on L2TPNS. We've learnt most of our stuff from reading the source, and experience.

heh, thats kind of the route I was afraid of going ... 

Thank you very much for this. I'm sure in the end I'll get to what I'm blindly groping for. =)



Quoting J <>:


I am running a series of Debian-based (amd64 kernel) servers running  the latest version of l2tpns (2.1.21-1.2).

I am interested in taking advantage of the clustering capabilities,  however the documentation is extremely poor.

First of all, can anyone refer me to better l2tpns documentation  with special regards to clustering?

As a bonus question, can anyone tell me how this would fit into my  existing (non-BGP-enabled) border firewall?  How are neighbors/peers  configured in l2tpns in  contrast to a physical security appliances'  configuration?  in case it matters, my border firewall is a Juniper  Netscreen ISG 2000.  If I am understanding what it will take to make  this work, I may also need another router in the mix; this would be  an SSG 140.

Basically, I know very little about BGP beyond basic definition.   However I really need to make my several l2tpns servers stop acting  as individual (degraded) clusters, and to begin functioning the way  l2tpns was written to work.

PLEASE help.


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