Two different PPPoE session through a single wireless CPE

RouterOS General
1

Setup:

MT RB532 (v.2.9.12) --> MT WRAP PRISM AP (v.2.8.28 --> wireless --> Tranzeo TR200-15 --> unmanaged switch --> customer's two different routers

I have a single customer who is requesting two seperate Public IPs. I'm running PPPoE and created two different accounts for the customer. He has two different routers connected to the unmanaged switch. Individually, either account works great, but will not work concurrently with each other logged in. Once the new one logs on it boots the other PPPoE session off. If you look in the PPP Active list it shows the same MAC for each PPPoE caller from this particular client. I'm learning this is because the Radio changes the MAC to its own MAC or so the radio vendor support says.

I think the problem I'm having is because the MT box's PPPoE servers sees the same MAC address (Mac of the radio TR200-15) for each router's login. I am allowing multiple logins in my PPPoE setup (see below). I also tried cloning the MAC of one of the routers, but still the same result only a different MAC.

Is there something else I can do to allow the MT PPPoE server to have two different PPPoE Users logged in but with the same MAC address? I'm trying to get this to work before I go the static IP route due to how I have all my QoS and Bandwidth limitation rules setup.

Thanks,

-CW

feb/15/2006 18:32:10 by RouterOS 2.9.12

/ ppp profile
add name="PPPoE_SOHO" local-address=XXX.ZZZ.WW.193 remote-address=PPPoE_Pool use-compression=no use-vj-compression=no use-encryption=no only-one=no change-tcp-mss=yes rate-limit=1200000 dns-server=XXX.YYY.78.13,XXX.YYY.78.14 comment=""

/ interface pppoe-server server
add service-name="PPPoE_Server" interface=CustomerSvc_Bridge max-mtu=1460 max-mru=1440 authentication=pap,chap,mschap2 keepalive-timeout=10 one-session-per-host=no max-sessions=0 default-profile=PPPoE_residential disabled=no

2

Actually, having the same MAC is not really to much of a problem.

But…

The PADIs for multiple PPPoE tunnels coming from the same MAC, MUST contain a host-uniq tag. Some routers do, some don’t.

It isn’t a MikroTik problem (MT PPPoE clients do include the tag, as does WinXP), it’s a problem with the RFC. In their infinate wisdom, the authors made the host-uniq tag optional, by using MAY rather than MUST.

It’s really hit or miss, even within the same vendor (i.e. some Netgear routers are fine, others are not). We ran into this many, many times, and other related issues to.

The only way to really tell, is to sniff the WAN port of the router, and manually examine the PADI packet. To learn how to read raw PPPoE, go here http://www.faqs.org/rfcs/rfc2516.html

In particular, you are looking for the 0103 tag, or the lack thereof.


Thank you RedBack and MCI, you have sucessfully made PPPoE dificult with MAC-NAT devices.

And thank you IEEE 802.11 group, for designing a protocol that makes such nasty hacks as MAC-NAT necessary in the first place.

Also, thank you SOHO router makers, for either forgetting the tag, or deciding to shave a tiny amount of development cost off your products, in the most inconvienient place.

Oh, and thank you Tranzeo, for not using MAC-4 (WDS), which would obliviate the issue.

–Eric