L2MPLS VPN or L3MPLS VPN?

alsayed · ‎03-04-2010

Hi Experts!

what is the situation in order to choose either L2MPLS VPN or L3MPLS VPN?

Thanks

Giuseppe Larosa · ‎03-04-2010

Hello Alsayed,

with L3 MPLS VPN a peer to peer model is used in the signalling plane: a single neighbor is needed the near PE.

no changes are needed to existing when adding or modifying an existing site, changes are confined to involved site and device(s).

L2 MPLS VPN provides one (or multiple) virtual LAN environments that span over the real sites over SP network.

L2 MPLS VPN is attractive if you need to connect at very high speed few sites.

When the number of sites to be connected is high scalability issues for routing protocols start to appear.

In that case multiple VPLS services need to be used.

In a L2 MPLS each CE device peers with all other sites connected to the same virtual broadcast domain.

routing is totally under control of enterprise and SP is not involved but as noted above scalability can become an issue if the number of sites is in the order of more then 40-50.

Mixed designs are possible with few most important sites interconnected with a VPLS service and remote sites using one or two L3 MPLS VPN services to connect to primary sites.

if you have only 10 sites as you mention in other posts L2 MPLS VPN with a VPLS can be a possible solution.

Hope to help

Giuseppe

alsayed · ‎03-04-2010

Hi Giuseppe

Thanks,what if u have 150 sites?

Giuseppe Larosa · ‎03-04-2010

Hello Alsayed,

I would go for L3 MPLS VPN with 150 sites: having all them in the same broadcast domain is simply a nightmare.

Using multiple VPLS circuits is not an interesting option.

Hope to help

Giuseppe

alsayed · ‎03-04-2010

HI

no dynamic protocol in use just a default route to the ISP/DSP,is it recomnded?

Thanks

Jon Marshall · ‎03-04-2010

alsayed@litani.gov.lb

HI

no dynamic protocol in use just a default route to the ISP/DSP,is it recomnded?

Thanks

Ali

It depends on your setup. If for each site you only have one router connecting you to the provider and these sites are not interconnected amongst themselves then using a static default-route works well.

If however for a number or all of your sites you have multiple entry and exit points and you want to influence which way traffic leaves and enters these sites then running a dynamic routing protocol is the way to go.

Jon