about L2TP

[hsasaki_cert]

Dear Sirs,

Please teach L2TP.

It thinks about the design with L2TP.

A in case of three sites, Headquarters(HQ), Branch1(B1) and Branch2(B2).

B1---HQ---B2

It is a star type.

At this time, is "B1---B2" possible?

It is a mesh type.

Best regards,

[globalnettech]

Hello,

are you saying that your current setup is a hub (HQ) and spoke (B1 and B2 as spokes) configuration, and that now you want to make it a meshed configuration, by adding a L2TP tunnel between B1 and B2 ?

Regards,

GNT

[hsasaki_cert]

yes, Is it possible?

[globalnettech]

Hello,

the config for the L2TP tunnel between B1 and B2 should look like this (the IP addresses are arbitrary, make sure you use those you have configured between B1 and B2):

B1

username B1 password 0 123456

username B2 password 0 123456

!

vpdn enable

!

vpdn-group 1

request-dialin

protocol l2tp

domain yourdomain.com

initiate-to ip 192.168.1.2

local name B1

B2

username B1 password 0 123456

username B2 password 0 123456

!

vpdn enable

!

vpdn-group 1

request-dialin

protocol l2tp

domain yourdomain.com

initiate-to ip 192.168.1.1

local name B2

Regards,

GNT

[ilya.varlashkin]

GNT,

wouldn't that configuration just prepare L2TP tunnel setup but actually do nothing until somebody calls router B1 (by whatever means that will end them up in vpdn-group) and then all they'll get is being L2TP tunneled to B1 and getting IP-layer connection from B1. Even if that is what needs to be achieved (strange), looks like there's race condition - vpdn configuration on each server doesn't accept any connection but only initiates and both are for the same domain.

[ilya.varlashkin]

if you want communication between B1 and B2 to logically be direct (although it will still have to pass via HQ as there's no other phisical way), then GRE tunnel seems to be more appropriate solution. With static GRE tunnels when you know IP address of the remote site in advance it's pretty simple and requires only specifying tunnel endpoints. It's however possible to make dynamic tunnel between B1 and B2 to come up when traffic exceeds certain threshold.