L2TP/PPP (adsl termination) problem

RouterOS General
1

Hi All,

I use RB600 and ROS 3.20 to terminate ADSL services. My telco uses some kind of ATM based (Layer2) DSLAMs and Juniper equipment as LAC. Juniper LACs open L2TP sessions to RB600 (LNS or BRAS functionality) and forward PPP sessions over it.
I use radius server to authenticate users and to give IP addresses (fix) or pools (dinamic range).

Almost everything works fine but I have two problem.

First problem is not serious. We cannot use L2TP tunnel authentication like as other (eg. cisco) LNSs can. ROS doesn’t seem to support it or I don’t know how to do.

Second problem is PPP session stuck. In some circumtances PPP sessions stucked-up on the RB600 when the user’s PPPOE session gone away (probably) irregularly. In this case I can see subsequent connection requests from the same user (same login name). User can connect if his service owns dinamic IP address but cannot connect if he use fix ip address because ROS cannot use the same ip address more than once. So, the user cannot login again until I remove his old stucked PPP session from the router.

I read many debug messages and can see two type of PPP sessions. Some PPP session use LCP echo request/reply feature while some PPP session doesn’t. Stucked PPP session are always the sessions which doesn’t use PPP keepalive. The other interesting thing is that L2TP control messages (l2tp keepalive?) are sending and receiving continously between LAC and LNS belongs to the stucked PPP session, so neither LAC nor LNS knows anything about that this PPP session gone away and should terminate this PPP and underlaying L2TP session.

Telco’s engineers said, PPP (L2TP) sessions should be terminated by LNS, everything is all right at their side. They have no the same problem with other customers who use cisco routers as LNS.

I don’t know how to solve this problem and I afraid I have to buy cisco equipment at last.
Is there anyone who has/had the same or almost the same problem like this ? Can it be a pppd bug in ROS ?

Any ideal wellcome!

Regards,
imedve

Mikrotik need VPDN!
2

Hi,

as I suppose my problem based on that ROS doesn’t send ppp echo requests in l2tp/ppp service. I cannot find any possibility to set this unlike in eg. pppoe-server settings.

Is there any way to setup and use pppd lcp-echo-interval and lcp-echo-failure options in l2tp/ppp termination (generic VPDN solution) ?

thanks,
imedve

3

Sorry I know this post is quite old :frowning: I’m about to do the same configuration here, is there any possible you can post your configuration on your RB600 please?

Thanks
:confused: