Hi,

I'm using Mikrotik RouterOS v6.42, I have a TP-Link RE450 that I'm trying to use as a wireless extender. Once it is set up devices connected to the network from the extender are not issued IP addresses. It works with my other wifi access point, but not the Miktoric Router OS. I can get a 'fake' extension by enabling the DHCP server on the extender, but that has been unstable, and doesnt really give what I want (one extended network with all devices visible.)


Is there some simple switch that is not allowing the mikrotic to issue IP addresses over the extender ?(something with the MAC / IP passthrough)

Any help is much appreciated.

My suggestion is to use 100% MikroTik and you will be happy. It will not have a high cost to replace this repeater.

https://wiki.mikrotik.com/wiki/Wireless_WDS_Mesh

Check out the wireless signal
Protocol used in both Ex: 802.11
Channel
etc.

Hi,


I have the same problem with the RE450. (This same problem also applies with the RE450 and a Draytek Vigor 2132 router).

I can see the DHCP offering from the Mikrotik hAP in the DHCP server leases list. It lasts 30 seconds (status offered) and then disappears.
By using the Sniffer tool in the hAP the handshake can be followed. Handing out and receiving the DHCP IP address goes well. But then the router does a verification with a broadcasted ARP request for that IP address. And the RE450 should answer that request (as a 2.5 half-bridge) with it's own MAC address (proxy ARP) or at least pass it on to the DHCP client.
There is never an answer on the ARP request and the DHCP IP address is dropped by the DHCP server, it does not come to the "bounded" status, as it does if the client is connected directly to the hAP wifi. The client never gets a proper IP address.

The wokaround with the DHCP served from the RE450 is not usable in a multi-user environment where IP address control is part of the LOGIN/passthrough authorisation. It also needs some reverse engineering of the IP plan of the original AP in all other cases. Very inconvenient.

Together with the lack of control of the used wifi channel in the RE450 (it's always auto and it assigns overlapping channels, eg. other than 1/6/11 ) this strongly reduces the usefullness of the RE450.

It looks like the RE450 is not handling DHCP requests as it should. Other repeaters like Engenius ENS202EXT and Draytek AP810 do this without any problem.

I have the exact same problem with a Mikrotik wAP AC (configured as AP) and a D-Link RE450(configured as a repeater).

Wireless clients of RE450 never receives a ip-address and the wAP AC just lists them as offered in log for 30secs and then times out.

Did you get a fix or workaround for this?

No, no fix or workaround. The TP-link repeater is the device showing the problem in a consistent way, it fails also for some other DHCP servers. However there are cases where only the DHCP server from Mikrotik fails to lease an ip address. Other DHCP servers do work with some of these other repeaters (like Edimax) where Mikrotik fails. Have done quite some testing .... viewtopic.php?f=2&t=116963 ... and there are many discussions with Mikrotik, who seems not to be able to reproduce the problem. And therefore claim there is probably no problem but only wrong configuration by the customer. DHCP address leases over halfbridges (2.5, changing the source MAC address in the in some packets, but sometimes not relaying broadcast packets) seems a delicate procedure. The idea of Mikrotik DHCP to broadcast the last step if it fails, is not good enough. The broadcast is using IP 255.255.255.255 OK, but the MAC address is not FF:FF:FF:FF:FF:FF , so it does not pass the repeater.

My newest experience is with the Mikrotic MQS. A Mikrotik device to make the wifi-ethernet transition. Software is not very clear, but that device does not allow for a Mikrotik DHCP lease between wifi and ethernet. Very similar to the 2.5bridge (universal repeater, pseudostation bridge , ...) experience.

May do some test later with a different DHCP server. If that one works, then there is a simple all-Mikrotik case

UPDATE: the RBMQS seems all to be a matter of sequence and timing. With the default configuration (DHCP client with fallback, no DHCP server) , connected to a mAP Lite with default settings for the DHCP server (except IP address range) . Connect MQS and mAP. Then usb power to the MQS. Wait 30 seconds at least. (Hope mAP was faster than MQS, and MQS has taken IP address) . Then connect laptop to MQS wifi. I get an IP address from the mAP. Can connect over L3 and L2 to mAP. There I see the IP address leased to the MQS. Can login via L3 web to the MQS.

Difference is the MQS DHCP server is OFF.

Have to check RE450 again! DHCP server is OFF, not auto ???. Once had a Linksys Home gateway WRT54G used as switch only, with DHCP server OFF, connected to the office network The whole department lost connection. The Linksys was sending a DHCP NAK for every DHCP request that was sent out. OFF meant something different than expected. Maybe the RE450 has something similar?

My current remediation is to let the RE450 DHCP server active, with IP adresses in the same subnet as the Mikrotik DHCP. Needs tweaking of that DHCP server whenever there is a change in the setup. On travel, you need to analyse the host wifi network first, and hope not to give out duplicate IP addresses.

Thanks, this is the same thing I ended up doing.

I have the RE450 connected to a wAP AC. wAP AC serves as a dhcp server from 192.168.100-200 and the RE450 also serves as a dhcp server from 201-254. The wAP AC runs bridge filter and prevents the DHCP packages to cross over between eachother.

Really ugly setup, but it works for now....

Briefly before setting this up, I tested the RE450 with a HAP AC2, and from I can rembember there were no issues with this DHCP IP Address assignment from the HAP AC2..., but im unsure

To continue on: "Have to check RE450 again! DHCP server is OFF, not auto ???. Once had a Linksys Home gateway WRT54G used as switch only, with DHCP server OFF, connected to the office network The whole department lost connection. The Linksys was sending a DHCP NAK for every DHCP request that was sent out. OFF meant something different than expected. Maybe the RE450 has something similar?"

I have done some more tests. (We know already that Mikrotik AP with DHCP server does not work over the RE450)

Using a Draytek router, Mikrotik wAP ac, and the RE450.
Following results with DHCP OFF (not auto) in the RE450.
With the Draytek used as DHCP server.
With the wAP connected via ethernet to the Draytek in its standard "AP bridge" wifi mode and bridged (ether1-wlan) , no DHCP

Trying to connect and get an IP address with a Windows 10 laptop, Android tablet (Lollipop) and smartphone (Android One)

Test results
wifi connected to Draytek: OK
wifi connected to wAP (Draytek- wAP): OK
wifi connected to RE450 (Draytek - RE450): OK
wifi connected to RE450 (Draytek - wAP - RE450) not OK

So it is not the DHCP server of the Mikrotik wAP, as it is never used, It is the DHCP last step in the handshake not passing over the wAP or RE450, when the client is not directly attached to the wAP

There are many documents about "DHCP not passing over bridge" in this forum .... and other documents in other forums.

If in the following text , BSAP is replaced with Microtik wAP (or RE450???) , I think we come close to the description of what happens.:https://supportforums.adtran.com/thread/4438
But even when the DHCP server is on the wAP it's not OK with the RE450. And that's confusing ... because the RE450 works with the Draytek

wifi connected to RE450 (wAP - RE450): not OK
wifi connected to RE450 (Draytek - RE450): OK

Well after the BSAP texts iI tought this was relevant in the Mikrotik bridge port setting:

learn (auto | no | yes; Default: auto)

Changes MAC learning behaviour on a bridge port
yes - enables MAC learning
no - disables MAC learning
auto - detects if bridge port is a Wireless interface and uses Wireless registration table instead of MAC learning, will use Wireless registration table if the Wireless interface is set to one of ap-bridge,bridge,wds-slave mode and bridge mode for the Wireless interface is disabled.

"Draytek (ether) wAP (wlan) RE450" link, wAP does not forward last step in DHCP handshake !? wAP is ROS 6.46.2, latest stable.

Tried to get away from the "registration table" only situation. (Auto?) in the wAP. Changed that and tried different combinations of flood settings on the interface.
No luck !!! Did not help!

Giving up, last try, towards the hAP ac2 with ROS 7.0beta4. Actually this is even a complication as the link is now....

Draytek (DHCP server) - (ethernet) - wAPac (bridged) - [AP bridge] - (wifi 5GHz) - [station bridge] - hAP ac2 (bridged) -[AP bridge] - (wifi 2.4 GHz) - RE450 - (wifi 2.4 GHz) - client

Guess what ... it works!!! No special settings used.

My suggestion is to use 100% MikroTik and you will be happy. It will not have a high cost to replace this repeater.

https://wiki.mikrotik.com/wiki/Wireless_WDS_Mesh

Check out the wireless signal
Protocol used in both Ex: 802.11
Channel
etc.

The link is dead.
Can you please point to wiki on how to set up a wireless repearer/bridge with mikrotik routers?
Must be 802.11 protocol so non-mikrotik devices can connect to the same wifi networks

Can you please point to wiki on how to set up a wireless repearer/bridge with mikrotik routers?
Must be 802.11 protocol so non-mikrotik devices can connect to the same wifi networks

This wiki article discusses different WiFi client modes available on ROS devices.

What you're after is the following: set AP device to mode=ap-bridge ... in this mode it will support both usual clients as well as "bridge-clients". The odther device should then be configured to mode=station-bridge ... making the pair (AP and "bridge-client") to behave as transparent L2 bridge. If you want "bridge-client" to act as an AP as well, then either add a slave wireless interface and set it up as AP (possibly mirroring main AP's security profile to enable wireless clients to roam between APs) or, in case your hardware is dual-radio, set up the second radio as usual AP (same considerations apply).