Problem with Bonjour Services and Airport Extreme In Bridge Mode

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Problem with Bonjour Services and Airport Extreme In Bridge Mode

I am using an Airport Extreme (802.11n) Base Station in an office environment with about 20 users. I have a firewall in the office which handles DHCP, so the Airport is in Bridge Mode and does not distribute its own IP addresses. The base station is connected to the rest of the network via its WAN port, which in turn is connected to a switch along with all the other wired clients. Wireless security is set to WPA/WPA2 Enterprise and authentication is done via RADIUS against a Leopard Server. Wide-area Bonjour is not enabled.

The issue is that sometimes (not always), wireless clients are unable to browse or use bonjour services. On a wireless machine, iChat will show no other users on the network (not even other wireless users running iChat), even though many users can see each other in iChat on the wired network. Wireless users also cannot print to Bonjour printers, while wired users have no problem. The printers are network-based, not USB, though they are connected to the base station's WAN ports, which are acting as a hub with the rest of the network in this case. Thus, I am especially perplexed by the fact the wired clients can see them fine while wireless clients cannot.

I have noticed that occasionally, iChat on wireless machines will inexplicably start working for a little while, only to stop working a short time later. My company also has another office with an identical network setup, and I have heard that a similar issue exists there, though reports seem to indicate that the problem is more occasional, i.e. Bonjour services work more often than they don't.

So what's the deal? Is this a bug of some kind in the Airport firmware? Do I need to configure Wide-Area Bonjour to get wireless clients to talk to each other and the rest of the network? If so, why? Shouldn't all the machines on the wired and wireless network be able to talk to each other, since NAT is not enabled on the base station? For what it's worth, the firewall does not control traffic within the internal network, so it's not an issue with ports being blocked. All regular IP-based services work, just not Bonjour. Any ideas or troubleshooting advice are welcome.

MacBook (Black), Mac OS X (10.5.2), Core Duo 2GHz, 2GB RAM

Posted on Apr 2, 2008 6:20 PM

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Answer 1

ianwestcott Author

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Apr 2, 2008 6:27 PM in response to ianwestcott

A little more info: It may be that this problem develops over time; when I restart the base station, everything seems to return to normal, and clients can see each other over bonjour again. Eventually, though, the problem will inevitably return.

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Answer 2

nodtmf

Level 1

14 points

Apr 3, 2008 7:44 AM in response to ianwestcott

Oh hi,

You should not need to enable Wide-Area Bonjour. I'm assuming you can't experiment in the an office environment, but since it is only the wireless clients that have a problem, what about changing to a "simpler" security method? Maybe Bonjour is having some weird interaction problem with the radius server.
My latest rant is that all these consumer grade routers/APs have a zillion features, and it seems once you start actually using some random number of features the device gets flakey 😟

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Answer 3

ianwestcott Author

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Apr 3, 2008 8:15 AM in response to nodtmf

I wouldn't be surprised if RADIUS was the cause, but I'd naturally rather rule it out as the culprit before abandoning it. We have 3 offices in total, all of which have the same Airport setup with the same authentication and encryption scheme. The idea was to make it as easy as possible for traveling employees to get online in other offices, while closing the loophole of people passing around a single password and letting non-employees onto our internal network. But I suppose when it comes down to it, a functioning network may win over a secure one. :-P

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Answer 4

jiceve

Level 1

20 points

Apr 3, 2008 8:19 AM in response to nodtmf

I use an old 8 RJ45 + 1 BNC ethernet switch, but it is connected like this to the base station :

Airport Extreme Wan port is connected to my ADSL modem Linksys AM200
Airport Extreme Lan1 port is connected to the Uplink port of the switch

I am using the DHCP router on the modem and the bridge mode on the Airport Extreme.

I am using WPA/2 settings on the Airport Extreme.

It works fine.

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Answer 5

Apr 7, 2008 12:51 PM in response to ianwestcott

I'm having similar problems with Bonjour services. I have two AirPort Extreme units in my home -- one is connected to a DSL modem and provides NAT, and the second is connected via ethernet to the first and runs in bridge mode. In my case, computers connected wirelessly to the first unit can't use Bonjour services -- printers, shared iTunes libraries, or auto-discovered AFP clients -- while computers connected wirelessly to the second unit or connected via Ethernet can.

I didn't notice this problem until the day I got my first computer with Leopard. On that day, I had several networking problems, so I reconfigured each base station. Unfortunately, that leaves me not knowing whether the problem is due to Leopard, or due to me leaving out a setting in the base station configuration. I've been through the configuration numerous times and don't see anything missing there. As for Leopard, I need to get a Tiger computer back in there and see if it still works.

I'll do that next, and also see if Bonjour service returns when I restart the first unit, as it does for you.

Meanwhile, I would say that if we're experiencing the same problem, then it's not caused by your Radius authentication -- which I'm not using -- or your running in bridge mode -- since my bridge mode unit is the one that works!

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Answer 6

bdonohoe

Level 1

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Apr 7, 2008 8:53 PM in response to Arlo Leach1

I seem to have developed the same problem with a new Express 802.11n I just bought. I replaced an older Express which had been working fine.

Here's my setup: an Extreme 802.11n (Fast Ethernet) is the router, sharing its internet connection wirelessly. The Express is configured not to accept wireless connections, but does bridge two wired clients into the network via 802.11n. The network is currently setup as 5GHz, n-only, but I've tried 2.4 GHz and g/n-mixed -- same problem in all cases.

With the old Express, the clients were always available via Bonjour. With the new Express, the wired clients will be visible for 10-30 minutes via Bonjour and then vanish. Those clients can still access the rest of the network, but can only see each other via Bonjour. It's as if that Express has created its own little subnet and cordoned off Bonjour from the rest of the network. Rebooting it returns Bonjour to normal for a few minutes...

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Answer 7

Apr 8, 2008 7:09 AM in response to ianwestcott

Okay, I did some more testing today. I have the two AirPort Extreme (802.11n) routers, plus a MacBook Pro running Leopard, and a MacBook and an iBook running Tiger. The routers were both purchased within the last year and are running the latest firmware, 7.2.1.

What I can see today is that the problem is not related to Leopard vs. Tiger, because it appears equally on all the computers. Also, it is not related to one router versus the other, because it appears on both. But it is related to restarting the router ... Bonjour will be available on a router when it first boots up, but after a period of time, it will stop. I can also confirm that this problem only exists over wireless ... even after Bonjour stops over the wireless connection, I can connect a laptop to ethernet to continue using the service. So, it sounds like we have a repeatable problem on at least four units?

By the way, I'm testing Bonjour by opening iTunes on each computer and sharing all the iTunes libraries. When Bonjour is running, each computer sees the other two computers' libraries. When Bonjour is not running, the shared libraries don't appear. This is an easy test, but more importantly, when Bonjour drops off I lose my printing and file sharing capabilities.

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