Posted: Tue Mar 08, 2011 1:39 Post subject: DHCP over Senao Bridge Fails
I have a pair of Senao outdoor devices set up as a wireless bridge. The configuration is WAN >router >firewall >BridgeAP >Bridgeclient >switch >clientpcs. The interface on the firewall defines the subnet for all the addressable devices downstream.
All was working well with fixed IPs but I now need to have DHCP on part of the subnet. The firewall device is the preferred DHCP server.
The problem is that instead of the bridge acting as though it was a "wire between two switches" the DHCP server only sees the Bridgeclient MAC address and quickly uses up all the addresses to it even though the request comes from a machine attached to the switch.
There is nothing in the documentation which explains this problem and I have read up a good number of posts here. I understand there are other wireless devices that have this problem. One reference suggested that a firmware upgrade would fix the problem. Is this likely and please could somebody point me to where I can read up on this to find solution.
I had an almost identical problem a couple of years ago and the thread is still there if you are interested.
In short the bridge will not act as though it was wired as far as DHCP is concerned and I do not think it possible. Sash pointed me to WDS but I didn't like that option at the time.
Here we adopted the option of having a DHCP server on the far side of the bridge to deal with downstream IPs and set up IP ranges on the "primary" DHCP server, which is the firewall, to prevent possible conflicts.
I am now in the process of setting up a similar configuration but shall probably go down the Access Point/Client Bridge route which enables you to have primary and bridged clients on same subnet. I write this with the confidence of ignorance and not yet having tried it. It is all in the wiki though.
Please advise if you found a way to have DHCP work over the bridged devices link.
I'm hoping I can get some new attention to this thread... here is my new spin on this:
We have a similar situation -- a wireless bridge connecting two network segments. The "A" segment has the master router, which is connected to the Internet, and is the primary DHCP server. On the other side of the wireless bridge is the "B" segment of the network. Users on that side weren't getting DHCP assignments. Static assignments work, but make it inconvenient for mobile devices (which come and go).
So, I activated DHCP on the router on segment "B" (the router only being used as a switch, only using the LAN ports). This cleared up some things (machines on the "B" side worked), but caused another problem. Computers on the "A" side of the network were getting their DHCP assignments from the DHCP server on the "B" side of the network, even though there was a perfectly working DHCP server on the "A" segment. I've since swapped out the "A"-segement router (and as a consequence, the DHCP server) with a completely new one (different brand/model/etc), but the problem persists.
1) DHCP *does* appear to traverse the wireless bridge, just not the way I want or need...
2) For unknown reasons, DHCP on the far side ("B") is being used by "A" side machines instead of the "A" side DHCP server... though it must be slower to do so, and that seems contrary to how this should work.
3) When "A" side systems get their assignments from the "B" side DHCP server, it makes them unable to get out to the Internet.
What I'd need/want is for all systems to work. Is that asking too much? To get there, I need either:
1) Machines on either network segment get their IP addresses from the DHCP server on that particular side of the network, or...
2) Machines on either network segment get their IP addresses from the DHCP server in the "A" segment.