Drawing 169.xxx.xxx.xxx IP address on LAN

[rayzon]

Greetings. I've pieced together a LAN and ran into a problem regarding IP addresses.

I have several switches on this network and everything worked fine up until I added this last switch.

I am using a Linksys WRT54GL with DD-WRT firmware running in DHCP mode to allow access to the WAMP server in my room.

I added an additional switch yesterday and was able to access the server from the user's computer. However, when I connected the other 3 users on that switch, they were not able to connect. The IP addresses of the three users was 169.xxx.xxx.xxx and the subnet mask is 255.255.0.0.

I did quite a bit of troubleshooting and had brief success with one of those three computers. I unplugged the power to the switch serving those users and the switch which supplies the new one. I rebooted the router and the server and when I went back to test, one user was able to connect to the server with an IP in the correct range (192.xxx.xxx.xxx).

I went to the next computer and the results remained the same even after the user rebooted and I ensured that all TCP/IP settings had been cleared.

After messing with his computer, I went back to the one that was working, swapped the Cat5 (we swap between networks, one for internet and one for the LAN) and connected to the internet successfully, but when I went to check if they could still connect to the LAN I never had luck again.

I turned off Windows firewall and each user's purchased firewall program, I tried numerous times to release/reset the connection via ipconfig. I reset the TCP/IP stack to original settings and now I'm at a dead end.

I hope someone can offer some kind of hope. I apologize for the chaotic post, but I really don't know how to explain this clearly, unless I actually managed to.

 

[mitchflossin]

Hello there... I can't say for sure what the specific problem is, but I can tell you why you're getting that particular IP address.

Windows has a feature called APIPA (automatic private IP addressing) that assigns IPs automatically when A) static IPs aren't assigned and B) the computer can't reach the DHCP server. You can read more about this feature here:

http://compnetworking.about.com/cs/protocolsdhcp/g/bldef_apipa.htm

So, the problem is the computers that are connected to the switch are unable to contact the Linksys router that's handling DHCP for whatever reason. I wish I could be of more help, but I'm not sure what the problem could be unless there's a loose connection or the connection between the two switches is plugged into the wrong port. Sometime there's an uplink button/port. Good luck.

 

[rayzon]

Thanks for the reply. I am somewhat familiar with APIPA. If I'm not mistaken, 169.xxx.xxx.xxx is in the public IP range, so I feel like that suggests something is kinda going in my favor. Instead of the computer drawing 127.xxx.xxx.xxx, etc.

I confirmed the switches do not have dedicated ports the other day when a helper asked if he needed to plug the cables in a certain way. I told him I prefer to do it a certain way but that it didn't really matter on these. He did it randomly and it worked fine.

I also checked the connections and they seem fine. Also consider that all three computers seem to be "kinda" connecting.

*keeping fingers crossed*

 

[mitchflossin]

Most of the 169 IP range is public... the private range is 169.254.0.1 to 169.254.255.254.

Is the last switch you added the same as the others in your network? What is the model number of the last switch you added? Is it a managed switch?

 

[rayzon]

The last switch I added is the same as the 3 I added previously. It is a TrendNet TEG-S80g.

Now as far as being the same as all the others in the network.....ummmm, no. I know that the preferred method is to use the same equipment, or at least the same manufacturer, but we're stuck here in Iraq and have to use what we can get our hands on. I have a lovely assortment of switches. A Cisco 2950, another larger Cisco, a Linksys SD208, and the TrendNets.

 

[mitchflossin]

Unless there are some faulty ports or the new switch is defective, i'm not sure what the issue could be. Out of curiosity, how is this new switch connected to the existing switches? is it daisy chained off of another trendnet? plugged directly into a cisco? Just curious...

 

[rayzon]

Okay, I hope this, I'll try to make it clean and clear.

Server
|---------Cisco
| |------------Linksys
| |--------------(can't remember brand right now)
|
|
|--------Cisco
|------------Dlink
|---------------TrendNet
| |----------------------TrendNet
|
|---------------TrendNet


....and maybe that is the problem, the last TrendNet switch. Hmmmm, I'll have to get in there and take it off to see. What sucks is the people whose rooms are housing the various components work alternating 12 hour shifts. Pain in the butt to try to get my hands on each piece.

 

[rayzon]

*editing the post seems to be a challenge*

Okay, I hope this, I'll try to make it clean and clear.

Server
|---------Cisco
|--------- |------------Linksys
|------------------------- |--------------(can't remember brand right now)
|
|
|--------Cisco
-----------|------------Dlink
--------------------------|---------------TrendNet
---------------------------|------------------|----------------------TrendNet
--------------------------|
--------------------------|---------------TrendNet


....and maybe that is the problem, the last TrendNet switch. Hmmmm, I'll have to get in there and take it off to see. What sucks is the people whose rooms are housing the various components work alternating 12 hour shifts. Pain in the butt to try to get my hands on each piece.

 

[rayzon]

Update...two computers on the switch that had the initial IP issues managed to connect just fine. These are not the first group of computers that were having problems, but a different group.

 

[mitchflossin]

Hey... sounds like you're making progress!

 

[rayzon]

Okay, well the Great LAN Spirits arrived and blessed off on my setup.

After many of hours of doing nothing more than troubleshooting, the problem has simply vanished without ever indicating what the problem actually was. I'm happy that it works, but annoyed that I didn't learn anything from it.

Thanks for hanging in there with me.

 

[Akram666]

Listen you get APIPA addresses when your DHCP server is not available or the DHCP server run out of IP address.

 

[mitchflossin]

Sounds like you got all the cobwebs out
Glad you got it working--stay safe and good luck!

 

[ruggieroav]

Hi!

Came across this thread, and I know this issue seems to be solved, but I just wanted to add a comment.

Seems the Trendnet switches you use have GREEN technology, which adapts power and network signal based on cable length. Using ONE of them in a basic network can be troubling if cable lengths are inconsistent, let alone using 3 or more.

If supply and budget allows, I would eventually go ahead and replace any "green" switches with their "regular" equivalent, not sure if that means you need to abandon TrendNet as a brand. If keeping with the Trendnet brand, The TEG-S8 works well, though it uses a plastic casing.