More than one PPTP client from same IP

RouterOS Beginner Basics
1

Hi everybody!

I was trying to connect more than 1 client from the same IP using pptp to a differents MT (all of them 2.9.50) but i failed everytime…
I just want to know:

  1. is that possible?
  2. what should I do , in order to do this?

pptp is enabled in ports.
the pptp server is working fine with multiple connection from different IPs…


please help me
thanx million!

2

Hi ;
I think you should use a router supporting the pptp , so you counfigure it’s wan port with the ip , username & password and the server ip which this router will connect to .
you also could make a MT OS work in the same way when you configure a pptp client with the interface will be connected to the internet .
and then you should do a NAT for the local network , so any one could go from the network to that MT you need to connect to .
to connect to more than MT , i am not sure if you could add more than one pptp client server with the interface .
with best regards .

3

Thanks ahmedsaffar,
But let me give you more details about this

we have a MT router supporting the pptp as a server, and we connect to that MT using the PPTP client installed on Win XP, and we don’t have any problems if the connection, no matter how many, are from different IPs.

let’s say i’m in IP “A”…make a VPN to the router, and can connect without problem.
some one in IP “B” try to vpn, and can connect without problems…
But if another machine in my office IP “A” try to connect, while the other VPN (from “A”) is established…the connection get refused…
so two connection from the same IP are not allowed..
why?

thanks for any help!

4

Hello again ;
when you say that there is a machine in your office with ip " A " is already connected to the MT , how this machine connected to the MT ? directly from the win XP or it behind a router ?
all your machines should be behind a router supporting vpn or behind MT had been setup as pptp client , so the pptp server see all these connections as one connection .
OR , you could make more than pptp accounts at the server to accept many connections coming from different IP’s .
with best regards .

5

ahmedsaffar thanks for your quick reply!

Let’s see, you’re right, there are two RB153 involved in this.
See the picture attach.
Only A is allowed to connect from A;B and C.
But if some one else want to connect from a different location to MT2, could do it without problems.
Question: what should I do to allow more than 1 PC from the same IP address to connect via VPN (pptp) to MT2 ?

thanks in advance to ahmed or anyone in the forum !
pptp.PNG

6

Hi again ;
Well be logic your MT2 is like a web site on the internet .
as we said before that in your MT1 there will be two interfaces :
ether1 → to the wan .
ether2 → to the local network .
and also we said that you are going to add a pptp client server to ether1 and provide it with the information required to establish this VPN .
you should add a NAT rule in your firewall with masquerade action to make all the connections from pc’s behind MT1 to MT2 looks like as it from a one client .
also you should check in the pptp server inside MT2 , if there is a limitation as one session per host .
i am not fully experinced with pptp , but trying to help you .
also i will do some tests on this .
with best regards .
:sunglasses:

7

Thanks a lot ahmed !

We have the rules that you mentioned already working from the beginning, but…we still can’t connect (+ than 1).
the masquerade is established for any outgoing traffic from WAN in MT1, and more than 1 connection is allowed in MT2 for pptp…

:confused:

8

anyone else that can help me with this ?
Normis?
any one?
please

thanks in advance

9

Hi again ;
try to read the following article , i wish it will help you .
http://forum.mikrotik.com/t/setting-up-a-pptp-server-was-how-do-i-configure/16558/1

with best regards .

10

Ahmed,
I really appreciate your time.
I read the topic, but seems to be related with another problem, and couldn’t get something out of it…sorry…
another ideas about this?, i was reading the forums looking for something similar, but it looks like i’m the only one with this issue?

any help
please?
should i moved this to the advance forum?
or is a rookie problem?

thanks

11

Hi.

it seems that I have the same problem.
Does anybody have answer?

Thanks

12

I have met this problem with PPTP past time. The problem is in Microsoft implementation of PPTP. There is a random session ID in the protocol, which helps to identify sessions on firewall. Microsoft forgot implement randomizing ID and the session still has the same IDs. Because the PPTP using sessions establishing from booth sides, the firewall with NAT is not able to identify incoming session (it from the same server IP, to the same port 1723, just the ID should be different) and forward the communication to the first established session.
Try to use different software client.