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cak
2008-11-22, 20:09
I'm trying to set up my SB2 as a wireless bridge. I plug in the device with a crossover cable (and power it up - that's important!). I get the prompt to turn on bridging and do so. It continues to try to join the network .. fine. Then DHCP fails.

This is 100% reliable. If I turn bridging off, it works again.

What gives?

radish
2008-11-23, 15:17
DHCP can be flaky with bridging, and it's usually the fault of the DHCP server - I've had all sorts of trouble with it in the past. Basically the server is getting confused as to why there are two devices asking for IPs from what looks to it like the same place. If the server was implemented properly it should work, but your best bet is probably to just use a static IP.

cak
2008-11-23, 16:04
OK thanks - I'll give that a try... though I would have thought that the bridging doesn't reuse the MAC address (that's why it's a bridge), so it doesn't look like "the same place" ...

peterw
2008-11-23, 17:02
Try a factory reset? All my SB2/SB3 use DHCP, and I've often used them as bridges for other devices. Neither the Squeezeboxes nor the bridged devices have had any trouble getting DHCP leases or using the network.

radish
2008-11-23, 21:32
OK thanks - I'll give that a try... though I would have thought that the bridging doesn't reuse the MAC address (that's why it's a bridge), so it doesn't look like "the same place" ...

The frame comes from the bridge, because that's the device which is actually connected to the switch or AP, and it has to be that way so the server knows where to send the response. The DHCP spec has a way of dealing with that (the server should use the MAC from a field inside the message, not where the message appears to be coming from) but I've seen servers get confused by that and do it wrong. Google "dhcp wireless bridge" and you'll see a bunch of posts about it with various routers.

cak
2008-11-30, 20:47
Um, ok. That's not how I define bridge in my mind, but that doesn't matter right now :-)

I played around some this evening with no joy. It leads me to wonder - is this meant to be a two-way bridge? I'm trying to get access to an ethernet stub that's attached to my squeezebox, which connects to the rest of the net via wireless ... not the other way around.

My problem at the moment is that the *squeezebox* doesn't get a DHCP reply - I'm not to the point of the bridged device failing to get a DHCP reply.

radish
2008-11-30, 21:17
I played around some this evening with no joy. It leads me to wonder - is this meant to be a two-way bridge? I'm trying to get access to an ethernet stub that's attached to my squeezebox, which connects to the rest of the net via wireless ... not the other way around.

What other way around could it be? The SB can only connect to an AP, it can't act as one. So it's got to connect to an existing net in infrastructure mode, once that's done the two wired segments should *appear* to be as one, and "direction" is irrelevant.



My problem at the moment is that the *squeezebox* doesn't get a DHCP reply - I'm not to the point of the bridged device failing to get a DHCP reply.
Have you tried it without DHCP? It would at least let us understand if it's simply a DHCP problem or something more fundamental.

cak
2008-11-30, 21:21
The SB can only connect to an AP, it can't act as one.

Ah. That's a piece of information I didn't have, though it makes sense.

I have turned off DHCP and the squeezebox is working ... but not obviously as a bridge. The device I'm bridging to will only do DHCP, so I'll have to do some more experimentation (and scrounging).

Does the SB have to be "on" to do the bridging? (powered on, of course)

seanadams
2008-11-30, 21:24
Does the SB have to be "on" to do the bridging? (powered on, of course)

Electrically powered on, of course. But no, it doesn't matter if it's in standby (or screensaver) mode. Those are really just UI states effected by the server.

radish
2008-11-30, 21:26
Does the SB have to be "on" to do the bridging? (powered on, of course)

No, it has to be connected to the network (i.e. associated) but it doesn't need to be connected to SN or SC (or actually even have a valid IP).


I have turned off DHCP and the squeezebox is working ... but not obviously as a bridge. The device I'm bridging to will only do DHCP, so I'll have to do some more experimentation (and scrounging).
Why not leave DHCP on for the router (so it's serving) and just use a static IP for the SB? The client can still make a DHCP request through the bridge, but it will avoid any confusion with the SBs DHCP requests. If it still doesn't work, then I think it's a classic case of your router not understanding the DHCP req coming from the bridge. You could sniff the session and look at the req/response to confirm (but you'll need a hub or some other way to get a PC in the middle of the connection).

cak
2008-12-01, 09:20
Why not leave DHCP on for the router (so it's serving) and just use a static IP for the SB?
That's what I did. Sorry I wasn't clear.

cak
2008-12-01, 10:15
Rather than clutter up my network with even more lashed-together crap, I took the easy route: I upgraded my dhcpd to ISC 4.0.0. It's working great now!