Hi,

I have encountered a problem using MLPPP with a PPPoE client interface, which I believe is the only PPP interface that supports MLPPP on the Mikrotik.
I am as confident as I can be that there is a problem, but would be grateful if one of the forum guru's would look over the information provided before I pass the issue to support.

I have been attempting to establish a two channel MLPPP session by having a Mikrotik, with a PPPoE client interface associated with both ether4 and ether5, connect to two independent LAC's that in turn tunnel using L2TP to a MLPPP enabled LNS. A diagram of the test setup is attached (Mikrotik MLPPP Test Setup.jpg). Apart from the PPPoE client, the only other interface configured is ether1 that connects to a SysLog server that was used to capture events.
In the test, ether4 is connected first. This successfully establishes a connection with the LNS via LAC 1, and is assigned an IP. The debug for this is contained within 'Initial ether4 Connection 010311.txt'. This document shows a successful connection and is useful for comparison purposes. I have added notes in an attempt to make the steps easier to follow. Apologies if they are inaccurate.

Once this step is completed, ether5 is plugged in, and this is where the problems start. 'Subsequent ether5 connection 010311.txt' is a debug of what happens. As with the other debug, notes have been added to make the steps easier to follow, however I'm not confident as to the accuracy of some of the interpretations.

What is happening, is ether5 attempts to establish multiple PPPoE sessions that LAC 2 passes to the LNS, rather than just one. Each session is then authenticated on the LNS. However, the LNS is configured to only allow a maximum of two sessions for MLPPP, so one is terminated.

The Mikrotik complies by sending a PADT to LAC 2. But as soon as this is completed, the Mikrotik immediately sets up another PPPoE session. This in turn is passed to the LNS which authenticates it, then terminates it as the max count has already been reached. This process continues indefinitely or until either ether4 or ether5 is unplugged.

Changing the roles of ether4 and ether5 (i.e. plugging ether5 in first) makes no difference.

In the config for the PPPoE interface, I use the default profile, however I also created a new one and tried changing all the configs, but without success.

I have tried both V4.16 and the most recent V5.0rc10 with the same results.

Increasing the number of channels allowed in a MLPPP session on the LNS only results in more channels being created, the Mikrotik doesn't stop at three.

Please accept my thanks in advance,

CAnder1

Hi,
A MLPPP setup just like this is on my to-do list. Cander1's post has made me nervous. Has any one got MLPPP going on multilinks ok? With which LAC / LNS? I was going to use Cisco.
Thanks!

Hi all,

Is there nobody out there who can confirm a working MPPP setup over two links using PPPoE with MT as the client?

Thanks!

Hi Mikroguf,

Thanks for the interest.
I should mention that it did work, just not very well. When the second link was added I started to get significant packetloss to the CPE (previously there had been none). Throughput testing showed that I was getting very close to 100% bandwidth utilization on the first link (the one that establishes without any issues), but only 60% on the other link (the one constantly opening and closing sessions). It was this performance that led to my investigating further and consequently this topic.