DHCP Across Bridge and EOIP

RouterOS General
1

Hi guys, I am having a terrible time getting what should be a simple solution working.
We have tested this before and it worked, so I know that it should be working.

We have to Mikrotik boxes, one is a RB333 with ROS 2.9.38 on it, the other is Intel based hardware running ROS 3.10.

I am setting up a system on a common /24 network which bridges the wlan interfaces on 10 MT boxes back to one central box (the Intel one) running as a hotspot. So I setup an EOIP interface for each system at each end, the bridge the wlan and EOIP interfaces together at the AP, the put the EOIP interface in a bridge at the hotspot end. The bridge at the hotspot end is then the interface for the hotspot.

This all should work, and the setup was shown at a MUM a while ago in a similar fashion.

For testing purposes I have removed the hotspot out of the equation, and am just running straight DHCP on the bridge at the hotspot end. If I assign static IP’s to the wireless laptops, they can ping through to the gateway address on the hotspot box fine, so connectivity and layer 3 is there and working, but, DHCP just won’t work. All interface settings are default, there are no firewall rules on either box, this setup is default config except the creation of the additional interfaces and wireless SSID, and the DHCP server setup.

The only thing I can think of is that something between EOIP on V2.9.x and V3.1 is broken, it just makes no sense to me.

Any help would be muchly appreciated.

Thanks
Paul

2

Anybody have any suggestions here ???

This should be so simple.

I have now built another box running 2.9.86 just in case it was an issue with 3.10 but it doesn’t work either.

I have even left the bridges and EOIP interfaces exactly the same and setup a PPPOE server at the other end and the wireless client can connect using PPPOE through the EOIP and bridges fine, but I still can’t get DHCP to work across them.

Any suggestions would really be appreciated.

Thanks
Paul

3

For those who may be interested, I found that obviously there is some sort of bug or incompatibility between EOIP on 2.9.x and 3.x.

I ended up building two boxes both running flavours of ROS 3.x and the EOIP bridging worked as it should straight away.

If there is a problem using 2.9.x and 3.x with EOIP this should be documented.

Regards
Paul

4

Just out of curiosity, did you check your arp=proxy-arp settings on each bridge/interface thoroughly?

5

Yes, tried proxy-arp and arp enabled on all interfaces from the wlan to the bridge at the core end.

When I did everything with 3.x I changed nothing, all the defaults just worked like they should.

Regards
Paul

6

so everything except dhcp crossed the eoip bridge fine? Weird …