Q: I have had wireless/DHCP problems with an Intel Centrino-based laptop and various access points. The first started with a Linksys access point. We could always connect to the access point, but obtaining an IP address either from the access point or from a DHCP server elsewhere (only one DHCP server turned on at a time) was a different story. The address was obtained on the first two or three times the laptop tried to get an address. After that, however, obtaining an IP address required rebooting the access point. This solved the problem for two or three times, then another reboot was required. We tried an SMC access point with similar results. Finally, we tried a 3Com Office Connect access point and have had no problems since. What do you think?

- George Kaplan

I don't have everything you do in my lab to be able to test the configuration you have see what I can find out first hand. With the situation you describe, it could be just the network card in the Centrino-based laptop or the access points (especially if they are using the same basic chipset/firmware) or a problem that involves a little bit of the wireless card and the access point(s).

It sounds from your message that the problem occurred regardless of whether the DHCP service was provided by the access point or another server on the network.

Check your firmware
I would check to make sure you have the latest firmware installed on the access point in question and the latest drivers/firmware installed on the Centrino laptop.

Since the network card is embedded on the Centrino motherboard, it may be necessary to get a BIOS/firmware update from Intel depending on whether the vendor using the motherboard has BIOS updates downloadable from its support site.

Since you have switched to yet another brand of access point and the problem has disappeared, that would seem to point the problem to something in the access point causing a problem with relaying DHCP traffic or generating that information itself.

To really see what is going on and get an idea of the potential cause, you will need to run some type of network traffic protocol analyzer such as WildPackets' Etherpeek, Network General's Sniffer product or Ethereal, an open-source protocol analyzer. Having a tool like this in your bag of tricks is not a bad thing. In fact, having more than one analyzer can sometime give you a different perspective on the situation that might have otherwise been missed.