Laptop and 169.x.x.x IP address problem

[VK2GOM]

It's done it again... occasionally, my shack laptop on my wireless network refuses to pick up a valid 192.x.x.x. IP address, and gets stuck with the useless 169.x x x x address, meaning it can't connect to the web. I have tried:

1. Rebooting the router.
2. Rebooting the laptop.
3. 'Repairing' the connection on the laptop.
4. Deleting the profile and re-entering the network password.
5. Run a Winsock repair utility.

Still no joy - it won't pick up a valid IP.

The thing is, it'll probably simply magically repair itself tomorrow, but does anyone have any ideas why it does this from time to time, and a quick fix?

The ISP is Bigpong, and the system is instructed to obtain an address from that, so could the problem be with them I wonder?

73 - Rob VK2GOM / G0MOH

[VK5ZK]

Hi Rob,

There are many different ways this type of home network can be set up so it is hard to generalise. Having said that this is how it normally would work.

The router will have 2 IP addresses. One for the "WAN" or internet side and one for the "LAN" or home network side.

The WAN IP will be issued by the ISP and unless you have purchased a Static IP address it will be different each time you login to the ISP.

The router LAN IP address will have a default and it is often 192.168.X.X.

The router can be set to issue IP address to each computer connected using a feature called DHCP.

Each computer can be set to request an address from the router or can be set to a fixed IP address.

The easy way is to use the DHCP function but it does require the router to be set to issue addresses on request and the computers must be set to request an address.

The DHCP IP addresses issued by the router will always be in the same subnet as the router LAN address.

You can wade through the router settings by logging in to the router from one of you computers. To login the computer IP and router IP must be in the same subnet.

To my knowledge there is no connection between the WAN and LAN addresses. They do not have to be in the same subnet.

This is my understanding of how it all works but I stand to be corrected. As I said there are many different ways this can be set up.

Garry VK5ZK

[VK2GOM]

Hi Garry,

Thanks for your post. That is about my understanding of it all too. I've tried the usual things as I mentioned, plus starting/stopping the DHCP service in Windows Services, as well as start/stop the QoS service - all to no avail. It either fails with a 0.0.0.0 IP or a useless 169.x.x.x

As soon as I plug a network cable in, it's fine, but just won't work wirelessly.

As soon as my just returned today globe-trotting wife has finished catching up on the desktop PC, I will re-reboot the router (again) and see if anything has changed.

I think the best solution will probably be to run a long network cable from the router downstairs, along the hallway, up the stairs to the spare bedroom shack and have it hard wired. More secure too I suppose.

I will probably keep trying it wirelessly on and off, as I'm sure it'll eventually just fix itself, as it has done before when this exact same problem crops up.

Don't you just love computers.... swear by them - and at them

73 - Rob VK2GOM /G0MOH

[VK2GOM]

***FIXED***

The strangest solution... go into the router setup page, disable WEP security (hmm), laptop then connects ok and grabs a valid 192 IP address.

When it's done that, re-enable security on router screen, disable wireless connection on laptop, re-enable it, reconnect to my gateway and it grabs the 192 address again OK.

One to remember I guess

73 - Rob VK2GOM / G0MOH

[VK2HCC]

Hi Rob, I had a similar problem with a Belkin USB wireless card, as with you it fixed itself when it was ready. After a few times of this happening I simply set up the desktop pc with a static IP address. Your router may need to be told that it has a static range (or what the DHCP range) is, just select something in the static range.

Craig

[VK4GHZ]

***FIXED***

Rob, do you have the latest firmware running in your router/switch?
Worth checking?

[VK2GOM]

Hi Adam,

I will get onto the Netgear website and check - although last firmware upgrade I did, Bigpond didn't like it at all... all sorts of connection problems. Had to revert back to the old version. I'll check the release dates on the latest one.

73 - Rob VK2GOM / G0MOH

[VK4GHZ]

Having suggested a check, I should practice what I preach.
http://kb.netgear.com/app/products/list/p3/161

Phew!!!
Still running the latest firmware v5.01.14 for my DG834G v4

Have 2 PCs in shack connected via ethernet, and another PC and notebook connecting via wifi.... all with no dramas at all.

[VK2GOM]

I have just checked too... the latest firmware available is the one that caused me a load of problems when I tried it. I'm not going there again! I'll keep an eye on it though and see if anything newer comes along in due course.

73 - Rob VK2GOM / G0MOH

Edit: Just noticed Adam, that is the same router as mine, and the firmware you are running is the one that plagued me with issues!

[VK5PJ]

Deleted

[VK4TU]

There are indeed 2 addresses;
1) An external address that's usually dished out of a pool by your ISP (a globally reachable address) (WAN)
2) A range of addresses (private, should never be seen on the Internet) used for your internal network (LAN).
Your router obtains your WAN address and then uses NAT (Network Address Translation) to hide your private addresses behind the WAN address.
Internally your PC uses DHCP to obtain a LAN address from the router which is set up to dish out internal addresses.
When M$ windoze PCs fail to obtain an address via DHCP they pick an address in the 169 network. You can set your network adapter to use a secondary address if it can't receive one via DHCP (it must be in the same range) but if DHCP fails usually assigning an address manually makes no odds as you can't talk to the router.
I'd guess that the issue is wireless connectivity between the router and the PC. Look for other things on 2.4GHz that may be interfering or attenuators between the router and PC. I'd certainly move from WEP to WPA2 (or at least WPA) if you can, WEP is crackable in about 60 seconds given enough captured information). WPA is more secure if you stay away from dictionary words in your passphrase.
Private LAN addresses are detailed in RFC1918 and are;
10.0.0.0 - 10.255.255.255
172.16.0.0 - 172.31.255.255
192.168.0.0 - 192.168.255.255

I hope that's of use - any networking questions just send me an email.

[VK2GOM]

Hi Joe, Thanks for the info... At least it's solved for now - until the next time it does the same again, probably once in th enext 12 months or so!

OK on the WEP... I don't think anyone in the neighbourhood within wireless range here is bright enough to run WZCOOK or Aircrack from a DOS prompt But yes - I am familiar with how to crack WEP keys - or should I say I know how it can be done.

73 - Rob VK2GOM / G0MOH

[VK4KGW]

Go to the Cisco site and download a copy of network magic , problem solved

[VK2JDH]

That address 169. is the default address windows gives to the network adapter if it can not get one automatically ( via DHCP etc ) or one is not manually configured in the adapter. So either the DHCP server on your router has a problem or your PC can not contact the DHCP server.

[VK3DXE]

You've tried the obvious things and installed a new driver and removed and reseated the wireless card in the laptop haven't you?

[VK6ADF]

Bear in mind that the thread the previous 3 messages are responding to is over a year old.

[VK2GOM]

...and my laptop hasn't done it since!

73 - Rob VK2GOM / G0MOH