Arp issues caused due to roaming and a repeater.

Ive run into an issue that i did not expect with my setup.

I had a dead zone that i had to service in a hotel hotspot network. here is the layout;

ccr router (hotspot, dhcp,firewall) → 2x MT switches (bridged) → 11 MT AP’s (bridged) → wifi Clients + 1 MT repeater(2ghz radio in station psuedobridge, 5ghz radio as AP bridge) → wifi clients.

What happens is, because of the station psuedobridge, when a wifi client connects to the repeater, the ARP entry shows the station psuedobridge mac. If they move and connect to a regular AP, they need to have the arp table change to the Clinet WIFI card Mac address otherwise they cannot surf. Unfortunately, the arp entries are not updating on their own unless you manually remove them or reboot the router.

There isnt really any other way for me to use this mikrotik repeater as the other modes do not support mixed clients.

Should i resort to scripting a flush of the ARP cache every, lets say 10 minutes, will there be any noticeable side effects? is there some other way to go with this problem?

Why do you think that pseudobridge is the only way to support “mixed clients”? Since your repeater is RouterOS and the AP it is connecting to is RouterOS, even in 802.11 mode, both station-wds and station-bridge are supported. Enabling one mode or the other will not mandate that “only” RouterOS clients can connect to your APs. See the wireless bridging modes applicability matrix. Note the “802.11” and “ROS 802.11” columns. “ROS 802.11” does not mean that your clients must all purely be RouterOS. It means that in order for the client to connect to the AP in that mode, that one client must be RouterOS, and the AP must be RouterOS. The AP can have other non-RouterOS clients associated to it as well and everything will work fine.

I think the solution to your problem is to set bridge-mode=enabled on all wlan interfaces across all of your APs (which should be the default value anyway) and then set your repeater to mode=station-bridge.

– Nathan

in the lab, when i tested it with station bridge mode, it worked for clients off the 2nd access point as expected.

However, when i connected my laptop to the first AP, I was no longer able to see the 2nd access point on the network. It appeared to have broken the bridging to the second AP as soon as I added a non ROS client to the first.

set bridge-mode=enabled is still on, I left it at it’s defaults. unless this is some kind of bug with rb912 hardware…

And of course it works just fine in station bridge mode here with different hardware… ill have to tinker some more.

I can’t imagine why it wouldn’t work; I’ve had station-bridge and regular stations connected to the same AP before with 0 problems.

If you truly find that station-bridge is a no-go (either because of a bug or some other issue), you might try using station-wds, which is closer to being standards-compliant than station-bridge is. station-wds basically is like a hacked-up wds-slave that doesn’t cause the station interface to broadcast AP beacons or allow a station to associate to it (except they must be doing something slightly non-kosher in the 802.11 framing because you can’t connect via station-wds to a WDS-capable, non-ROS 802.11 AP, which seems like should work).

station-wds does work a bit differently in that it will cause a virtual WDS interface to show up on the AP. You will need that WDS to be a member of the same bridge that your master WLAN AP interface is in. You can either create a static WDS interface (bound to the MAC address of your station-wds client) and permanently add it to the bridge, or you can tell RouterOS to dynamically create one and tell it that you want that dynamic interface to be automatically added to a bridge of your choosing.

– Nathan

I have it working in the field. Im not sure why it was giving me trouble… i probably forgot to clear arps when i changed it over.