L2TPv3 design and implementation

fdeatoug · ‎08-16-2003

Hi all,

I've got a design question. The question is:

We have 5 sites which will be connecting to each other in a ring/hub fashion via WAN links. The application that is going to be deployed requires bridging on the one VLAN across all sites. I've looked at www.cisco.com for examples on this but can only find examples of two sites connecting to each other using the technology. Is it possible to configure it to work in a ring fashion?

Thanks for any help!

Frank

rsissons · ‎08-16-2003

There is nothing to prevent you from connecting your sites in a physical ring topology. Spanning tree will negotiate one unique path though the network to prevent loops.

fdeatoug · ‎08-17-2003

Hi rsissons,

Thanks for the reply. I thought as much but I didn't want to complicate the original posting by mentioning all of the technical details. Here goes...

Essentially the network comprises of multiple VLAN's at each site. One for voice, one for data and one for WLAN. Throughout the infrastucture QoS and security are **Essential** - therefore I wouldn't like to go down the bridging route.

Now the the voice solution which is going to be implemented but the call managers which are going to be used need to communicate across a sort of shared VLAN throughout the 5 sites. This allows a sort of HSRP failover scenario for the call managers.

After reading all of the documentation available on www.cisco.com, VLSP isn't yet available as it's still in IETF draft. My last option is therefore seems like LT2Pv3 ethernet tunnels - right? So now after doing the research all I can seem to conclude is that I need 2 ethernet interfaces per router in this scenario to achieve a full transparent bridging solution across the ring.

It seems the ethernet interface can only map to one remote point not multipoints therefore I think I need more than one ethernet interface per router to achieve this. or am I missing something completly?

I don't have 3 switches and 2600 routers with enough interfaces to test this out so I would REALLY appreciate some advise on this. Surely somebody else has tried to achieve this?

Essentially it's the same as what Elan's achieved with ATM years ago to create a MAN.

Regards,

Frank