Hi,

Ik have 2 Mikrotik routers. They are connected over the Wan by a PPtP connection. MT-1 has tunnelIP 10.0.1.1, MT-2 has tunnelIP 10.0.1.2. Everything goes well and is working. Over this PPtP tunnel i want to create an EoIP tunnel. I configure the tunnel both ends with ID=1 and on MT-1 to 10.0.1.2 and on MT-2 to 10.0.1.1. So far so good. MT-1 is connected to a bigger LAN and has several VLANS. In 1 of these VLANS there is a DHCP server. I created a bridge to bridge the VLAN interface and the EOIP tunnel on MT-1. On MT-2 i created a bridge and added the EoIP interface and ether5 interface.
When i connect a PC to ether5 on MT-2 i do not receive an IP address.
Here comes the strange part, when i modify the EoIP tunnel so that it does not use the PPtP tunnel but both MT routers setup the tunnel directly over the internet by using the public IPs of the MT routers the PC on ether5 does recieve an IPadres. This tells me that the setup is correct also are the bridges.
Again i modify the EoIP tunnel to use the IPs of the PPtP connection and again no DHCP IP received by the PC on ether5.

I thought it might be the MTU size. I have seen that the MTU of the PPtP connection is 1450 so i changed the MTU of the EoIP tunnel on both routers to 1410 and several lower values. This doesnt work, still no IP.

Can anyone help me with this issue since i have no idea where to look anymore.

Thank you very much.

Why use the PPtP endpoints at all? You will not benefit from building the EoIP ontop, and as you already mentioned, MTU is degraded also.

Are you looking for encryption with the EoIP tunnels?

No, if EoIP are working, he want connect two computer with PPPoE...

scotthammersley,

Yes i want to have encryption for the tunnels als some of the B sides have dynamic IP's and using PPtP eases that. Any other ideas to do this?

I would suggest using IPSEC to encrypt the tunnel endpoints. You could build that as a hard tunnel, but I would suggest then using the EoIP tunnel for physical route points.

ok, i could try that but what specifically do you mean by

but I would suggest then using the EoIP tunnel for physical route points

?

I just tried this yesterday and had the same result: DHCP doesn't work across the EoIP tunnel which is over the PPTP tunnel.
Interestingly, I statically assigned an IP address and gateway to my laptop and everything worked! The EoIP tunnel transported DNS requests and TCP traffic to external websites on the other side of the tunnel.

The only thing that doesn't work is dhcp. Like you, I suspected MTU issues, but dhcp requests are very short packets, while the TCP/HTTP packets are large and they worked fine.

I suspect something is going wrong with broadcast packets, but I can't figure out what that might be.

Yes, like you, I am using pptp for encryption.

Have you gotten any further with this?

As a side note, I previously used PPTP tunnels (without EoIP) and specified a bridge name in the PPTP profiles on both sides. This creates a transparent tunnel between the bridges on each router. This used to work great, then it stopped working, but I don't know when. I think it was ROS 5.x. This is why I resorted to EoIP over PPTP.

your first stop is packet sniffer. In most cases, it is the last stop too.
might be a similar issue to one described in this topic:
http://forum.mikrotik.com/viewtopic.php?f=2&t=81597

Thanks for the link, CblP. Unfortunately, that's not my problem.

I am using PPTP to link two bridges, one on each of two routers separated by the Internet. I do this by entering the bridge name in the "Bridge" parameter at each end (client/server) of the PPTP configuration.

By doing this, Mikrotik says that ALL packets, including broadcast packets, will flow between the two bridges via the PPTP link.

After using Packet Sniffer, I see broadcast packets leaving the bridge on one side, but not showing up on the other side.

If I assign manual IP addresses to each bridge, I can ping between them.

But, If I create a dhcp server on one bridge, and dhcp client on the other, the broadcast dhcp packets from the client never get to the server.

This used to work when I used ROS 4.x. I don't have any 4.x versions anymore, but it sure doesn't work in ROS 5.x and 6.x up to 6.17, which is current as of today.

The Mikrotik Wiki mentions BCP (Bridge Control Protocol), which is used to allow bridging over PPTP. According to the Wiki, it is enabled just by entering the bridge name in the PPTP configuration at each end. Well, I do that, and it no longer works.

Any further suggestions would be greatly appreciated.