Mpd-4.2 released.

Ovi ovi at
Wed Jun 27 12:28:38 UTC 2007

Dear Alexander

Thank yoo for your email, it is very interesting.
I am not very familiar with BGP (but I will learn), my question is: did 
you use multiple pppoe servers with different subnet for every pppoe server,
or you have high availability with every serverer giving IPs from the 
same pool of addresses. I am using Radius, and I would like to have 
configured the
pppoe servers the same way, so if I would need more power, I would add 
another server, that would offer pppoe connections from the same pool, 
using the same
radius server as everyone. I think if bgp sessions are estabilished 
between router and pppoe servers, every pppoe server would have his own 
subnet of addresses
to give to users, which is not good, it will be interesting every pppoe 
server to accept all users. So not have pppoeserve1 for 100 customers, 
pppoeserv2 for another 100 customers and so on.

The second issue I've encountered , on my setup I've connected router to 
two pppoe servers, and on pppoe servers decond network card of both 
pppoe servers
was connected to our LAN. Because all users from lan already have setup 
pppoe on their workstations, I wanted to transparently for them make 
this system work.
So, I setup both pppoe servers with the same name (same hostname), and 
also the service name is *.  Still the load is not balanced, most of the 
users connect to one server, and only few of them to the other. It is a 
posibility that the fastest pppoe server who answer to establish the 
connection with user?

I've searched a lot for those issues, I did not found much information 
on the Internet, maybe you know some resources for me to study.

Thank you
Best regards,

Alexander Motin wrote:

>Hash: SHA1
>Ovi wrote:
>>Also as you know
>>PPPoE is vulnerable to arp poisoning and to DoSs. Having a small network
>>with 10-20 computers using mpd is easy, but having 2000 users or more,
>>things changes, problems appears. Solving arp poisoning or DoS attack
>>(sometimes caused by a burned switch port which mixes RX with TX) I
>>thing can be done using a Layer2 managed switch, with ACLs, I will try
>>and I'll inform you.
>Even if pppoe have some DoS weaknesses it also have some protection
>mechanisms against it. It's a pity but ng_pppoe originally implements
>protocol in a way which does not allow this protection to be effectively
>As I have told 4.2 release contains overload protection which should
>also help against DoS attacks. I am not sure it will be able to handle
>100Mbit/s flood of PADI requests from broken switch, but should avoid
>mpd freeze in such case.
>>When having many users, it is useful to have high availability, so it
>>would be nice and useful to setup multiple pppoe servers . I've tried
>>that, using a router, connected
>>to 2 pppoe servers, and at every pppoe connection, a route was added to
>>the router  and when  user  disconnected,  the route was deleted from
>>router.  This is still a buggy implementation, we had problems messing
>>up routing table.
>Having several PPPoE servers in one segment is a normal solution
>protocol. It is not so efficient now as it could be due to ng_pppoe
>implementation problem I have told, but it still should increase
>performance and stability.
>What is about routing problems, you just should find good dynamic
>routing solution. I have successfully working network with hundred PPPoE
>servers and many thousands of users with routing successfully managed by
>quagga bgp.
>- --
>Alexander Motin
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