Routing

Hi, expert.

Can you explain technique for implement L2VPN (not VPLS) full mesh forwarding ethernet packet. Are there any kind of MAC learning on PE routers?

L2VPN is basically p2p pseudowire and doesn't learn MAC. I don't think we can implement P2MP L2VPN.

VPLS is the solution for such requirement.

My understanding too that L2VPN is p2p architecture, but I read some juniper documentation and will surprise with this phrase

"The remote site ID allows you to configure a sparse Layer 2 VPN topology. A sparse topology means that each site does not have to connect to all the other sites in the VPN; thus it is unnecessary to allocate circuits for all the remote sites. Remote site IDs are particularly important if you configure a topology more complicated than full-mesh, such as a hub-and-spoke topology."

http://www.juniper.net/techpubs/software/junos/junos95/swconfig-vpns/id-10535747.html

Draft Komplella provide procedure to calculate label for more than one remote site in VPN. And whether this phrase mean that I can establish at least p2mp tunnel from local site without use remote-site-id. And if yes, how router will decide to which PW send ethernet label.

Hey there,

 remote-site-id has more to do with default site association rules. Imagine a PE-1 with site CE-1 that has multiple interfaces.

 By default, the order of interfaces under CE-1 in the configuration are relevant. In other words, the first interface will get a site-id=1, each following interface's would be incremented by 1and default inheritance will be increased by two when remote site id equals local site id.

 With remote-site-id knob, you have more control (and sometimes visibility) over this association mechanism.

 For example

[...]

site CE-1 {
site-identifier 1;
interface fe-0/0/0.30 {
remote-site-id 3;
}
interface fe-0/0/0.20 {
remote-site-id 2;
 }
}

 

is equal to:

[...]

site CE-1 {
site-identifier 1;
interface fe-0/0/0.20 {
 }
interface fe-0/0/0.30 {
  }
}

Note that the first interface get remote-site-id 2 because the local id is 1.

 In short, there's still no mac learning involved.

Hope this helps,

Many thanks! Great explanation