MacBook Pro will not connect to Cisco Wireless Network

I have just bought a brand new MacBook Pro, running Leopard (OSX 10.5.1) and I just cannot get it to connect to the Wireless Network at my workplace.

The MBP connects to wireless network and authenticates just fine, but will not obtain an IP address from the DHCP server.

The wireless network consists of 16 Cisco Aironet 1200 Access Points controlled by a Cisco Wireless Network Controller. It does not broadcast its SSID and is WEP 128-bit hex protected.

Changing the network from WEP to WPA is out of the question for me as this is under the control of my customers IT Department and they do not have any problems with their PCs connecting to the network. It appears to be an Apple issue.

For reference, my old Vaio PC, my Nokia N95 and my iPod Touch ALL connect to the same wireless network without any problems whatsoever, first time, every time!

If I boot into Windows XP from my Boot Camp partition, XP can connect wirelessly to the network without any problems, so it is not MacBook hardware related...

It has to be a bug in Mac OSX... doesn't it?!?

Things I have already tried (following suggestions on many forums):
* Switching Airport off/on
* Deleting various network-related Plist files and rebooting
* Manually assigning an IP Address (not really permitted but doesn't work anyway!)
* Disabling all network adaptors except Airport

AP Grapher shows that the MBP is connected to the wireless network, at good strength, and packets are being sent and received, but Internet Access is not possible as no IP Address has been assigned. Instead, my MBP shows a 169.* IP Address (self-assigned). It should be a 10.1.255.* address.

Can anybody please help? Thank you.

MacBook Pro 17" Intel 2.4GHz 4GB RAM, Mac OS X (10.5.1)

Posted on Dec 10, 2007 8:24 AM

56 replies

Apr 1, 2009 4:31 PM in response to SJRNET

Wow... its funny to see this going on for a quite some time. Its the ethernet preamble setting on the wireless APs. I run both Cisco 1100 and 1200 series both in autonomous mode and lightweight (LWAP) mode with WLC4400 controllers. So my Macbook Pro works fine (last year model) and I have another MacBook (new model) that didn't work correctly. So in 802.11n, I believe the preamble field is optional. This may cause compatibility issues between the older B/G signals. Which was what the preamble field in the ethernet frame was originally used for, to distinguish the differences between the two formats.

1. so on the Aruba Wireless Controller or Cisco Controller, I switched the Ethernet header preamble to "short" and it works on my new MacBook now with the 802.11n wireless.
2. if that doesnot work, remove any proprietary header frames such as Aironet extensions
3. if that also doesn't work, disable proprietary MPF (management frame protection).
4. You may need to delete and retype the WPA keys with the related SSID.

Apr 23, 2009 12:56 PM in response to autobot130

Thanks for the detail, but unfortunately still a no go for me. I have a new unibody MacBook that refuses to connect in one location on our school campus to a hidden SSID. Other, older MacBooks connect just fine. I've even broadcasted the SSID to test and it would not connect.

When I move to another location on our campus, it does connect and will stay connected even when I go back to the original location and with full bars. It also connects to wireless in places off campus.

I've rebooted our Cisco wireless controller as well as a few of the Cisco 1131 APs near the dead zone.

I'm at a complete loss. Any help would be appreciated.

stephbu

Level 1

0 points

Apr 29, 2009 6:51 AM in response to NeilWalsh

I experience DHCP issues with WPA2 Enterprise auth and no-doubt Cisco AP kit around our corporate network (several hundred access points across 50-60 buildings). On those that fail - the machine authenticates correctly - but then fails to acquire an address leaving me with a private address. You

It must be something to do with MBP/AP configuration/compatibility for sure because it works in many location just fine. However after recent (I'm pretty sure 10.5.5) updates AP's that worked just fine ceased to work.

Of course my WIndows brethren laugh as their supposedly inferior Dell, Lenova and Tosh machines connect just fine.

Wireless Card Type: AirPort Extreme (0x14E4, 0x8C)
Wireless Card Locale: USA
Wireless Card Firmware Version: Broadcom BCM43xx 1.0 (5.10.38.27)

SonicU2

Level 1

0 points

Oct 27, 2009 9:04 AM in response to stephbu

This has been going on for ever, we are just trying to get this working over Cisco A1200's using Snow Leopard. Same results, it authenticates but will NOT get a DHCP address?

Did anyone every get it to work?

Nov 21, 2009 4:41 PM in response to SJRNET

Just a thought because my employer authorizes the individual hardware (by MAC code). If your hardware wasn't in the approved list of MAC's you could see the network, but couldn't get an IP address. (even if you had the wireless WPA password)

Jan 7, 2010 6:26 PM in response to SJRNET

Has there been any resolution to this yet.
I've had the same problem as the OP ever since I got my Mac. Seems to work perfectly with other access points. Just having problems with the Cisco's APs at work. My shiny MBP and I are the laughing stock at work as all the other Thinkpads have no problems.

Jan 8, 2010 10:56 AM in response to SJRNET

Does anyone know if this is a leopard/snow leopard thing or an airport thing?
Would I be able to use a usb wifi adapter?
because I would prefer to use the macOS and parallels to access my windows and not have to go through boot camp.

Jan 12, 2010 1:37 AM in response to SJRNET

Once again, another reason Apple has not, and will not penetrate the business market. Simple things like business grade wifi connectivity don't work and are not addressed by the company. I doubt they ever will address it.

Spiff

Level 1

129 points

Feb 2, 2010 3:58 PM in response to SJRNET

This thread was recently brought to my attention. My site was running Cisco APs in lightweight mode (specifically 1252s in B/G/N + A/N HT20 mode, but I don't know that it matters), in conjunction with various models of Cisco Wireless LAN Controllers (WLCs) and Wireless Service Modules (WiSMs).

Even without any security enabled on a certain network, some Mac clients would sometimes fail to get DHCP leases. 802.11 monitor-mode packet traces, in conjunction with wired Ethernet packet traces between the APs and the controllers (showing the unencrypted LWAPP session) showed that the clients were successfully associating and sending their DHCP Discover packets, and the DHCP server was replying with a DHCP Offer, and the WLC/WiSM was forwarding that DHCP Offer to the Cisco AP, but the Cisco AP was never forwarding that DHCP Offer along to the client.

This was determined to be this Cisco bug:
CSCsy73154—The access point does not forward the DHCP offer to the client.
...which is sometimes called:
CSCsz22901—The access point does not forward the DHCP offer to the client, so the client fails to get an IP address.

These issues were fixed in the following Cisco WLC/WiSM software releases from the summer of 2009:
4.2.207.0 (not to be confused with 4.2.205.0 which does NOT have the fix)
5.2.193.0
6.0.x.x -- I believe any public 6.x release has the fix.

If your site is running a 5.0.x.x or 5.1.x.x release on your Cisco WLCs/WiSMs, you'll need to evaluate upgrading to 5.2 or 6.0, because I think if Cisco was ever going to fix this for those build series, they would have done so by now.

Andyyy

Level 1

0 points

May 20, 2010 10:30 AM in response to Frederic Haubrich

Had one MBP at work that would not connect to our cisco network. Tried this and so far after a couple of reboots it appears to be working. Thanks, appears to be working for me too.

Naetimus

Level 1

8 points

Sep 15, 2017 7:58 AM in response to SJRNET

It is the encryption settings on the Cisco (at least it was for me).

My router was set to TKIP

I changed to AES CCM and it worked great.

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MacBook Pro will not connect to Cisco Wireless Network