Limited or no connectivity (or connected with limited access) (or the dreaded 169.*)

Question

We've probably all seen it at one point. It's the worst type of problem to troubleshoot.

You get that IPv4 address starting with 169.*

Windows XP will tell you nothing, but will offer to renew your IP. Vista will offer to diagnose the problem which isn't often helpful.

My question is: Does my operating system really not know why I've failed to connect to a network? I know you know when I haven't entered my wireless key properly - why don't you make it easier on me for a change

Answer 1

I would think in the majority of circumstances, the DHCP client has failed to obtain an IP address, which leaves the system without network connectivity.

Since this might confuse the end-user, perhaps MS has opted not to display this message only says "limited connectivity" (or whatever Vista says)

Answer 2

I know you know when I haven't entered my wireless key properly

sometimes it doesn't even know that! :)

only very recently i had the case where a client used a hyphen rather than the correct underscore when entering the WLAN key, Windows then connected to the router alright but of course only 'limited'. now that can drive you really crackers :)

Answer 3

I understand why you are confused by that message. A 169.254.x.x IP address is called an Automatic Private IP Address (APIPA) and it's standard practice when you are configured for DHCP but are unable to get an IP address from your DHCP server, or there is no DHCP server by design.

The problem is, this message is coming from a part of Windows that doesn't know anything about the wireless connection process. This module, whatever it is, has given up on trying to get a DHCP assignment, but it doesn't know it is because the wireless connection protocol has failed (due to a bad key or other configuration error).

The Windows wireless module is absolutely silent. Some laptop vendors have tried, with limited success, to replace the Windows silence with better tools, but the integration leaves a lot to be desired and that stupid yellow ball continues to roll back and forth, confusing everyone.

Windows 7 seems to work better. Ubuntu is better. XP never will be fixed. Just assume that your wireless access protocol is set incorrectly or, more likely, the key is mis-typed, or needs to be entered again. Then wait for Windows 7. :-)

Answer 4

As for your actual question, I don't think there is any good operating system that fully knows why it has failed.

I quite like Windows and in Internet Explorer - the troubleshooter that looks at NAT, connections, and a ton of other things.

However, I quite like the limited network. When you need it, its nice to know it works... you can connect as many xp+ (but vista/7 is much better) on a quick hub, ad-hoc wireless, or cross-over ethernet cable, and they automatically work without needing DNS, DHCP or all the usual stuff.

The only real difference is Apple who call it a feature, Bonjour, it is almost the same thing.

In linux, I have not seen any similar feature in the distributions I use. Typically all I have seen is it either works with DHCP or staic IP, otherwise you don't get a IP.