Wireless, still have data-link, but lost TCP/IP

Posted on 2003-11-16
Medium Priority
Last Modified: 2013-11-29
All machines run win2k. The DI and DSL have HTTP based setup facilities.
Configuration is as follows:
2 to 4 PCs connected on ethernet via a Dlink DI-614+ switch/router/wireless AP.
1 PC with a wireless and an ethernet interface, but normally working wireless.

Everything was working file, all PCs were using the DI for DHCP, all in a typical 192.168.0 subnet, with the DI being, gateway for all.

And I got an ADSL modem (Dlink DSL-300G+). The DSL was an IP which cannot be set:

Fortunately, I can set the IP of the DI, so I had to make it Do I did that, and configured all PCs with the new gateway IP. Ok.

The I connected the DSL on the DI, and I couldn't access it at all. After RTFM, I had to change the IPs of the rest of the network to 10.0.0.x! Dlink sells these two appliances so that they will work together. So I follow the manual.

After that, the DI is, all wired PCs on the DI are 10.0.0.x ( etc), and indeed I can now access the DSL ( --manual was right :)

THE PROBLEM is that after making the above changes, the last PC (on the wireless interface) can no longer see the rest of the network! The interface utility shows perfect signal, but I cannot connect nor ping to anything. If I plug a wire, it can see the network just like the rest of them boxes. But NO longer on the wireless interface. I also tried to disable the ethernet i/face, but no good. The wireless has data link connectivity, but no TCP/IP at all. It's IP is 10.0.0.x just like the others (gateway but nothing is happening.....

I cannot imagine any new ideas to try... so I'm all ears! :)
Question by:harvk
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LVL 31

Accepted Solution

qwaletee earned 1000 total points
ID: 9761255
First sonme background and side points...

The 614 has LAN and WAN ports.  The 300 goes into its WAN port.  The wired PCs go into the LAN ports.  The wireless PC si effectively "plugged into" a LAN port, because the wireless AP (access point) internal to the 614 is connected to an internal "LAN port."

Betwee the WAN ports and the LAN ports (including the AP LAN port), sits an NAT router/firewall.  This effectively separates thenetworks, including the address space.  The 614 itself has tow addresses -- one for the WAN port, one for the LAN port.  So, if you have plugged things in as I described, then you would be OK to have internal address for the 614 AND have the SAME address on the 300!
LVL 31

Expert Comment

ID: 9761260
Next... why wireless isn't working.

the first thing I would do is disable the wireline card.  That's because you may be "confusing" WIndows, because both cards seem to be valid, and both may be using the same address space.  In taht case, the routing tables may be giving the wired card preferennce, and all traffic is trying to go out on the unplugged card.  By disabling that card, al traffic will go out on the 802.11 card, and you'll be OK.

Author Comment

ID: 9763828
WAN/LAN connections are alright.

On the wireless PC, I have disabled the ethernet i/face with no results. It's onboard, so I cannot remove it.

If the problem was entirely routing, I would expect the ethernet i/face to have problems as well. But it could be also a matter of luck... But again, with the eth disabled, it should work.

As I described earlier, it is NOT ok to have It didn't work. And at the time I hadn't read the manual. I also contacted the tech support, which just said the same with the manual.

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Expert Comment

ID: 9765933
on that last Wireless thing look and see if there are any changes in comparison to the routing table from one of the PC's fed with cable, I think not ? is there any "old" routes in the routing tables persistent maybe added along the way.

Or i must comply with qwaletee its a firewall problem in between the virtual "interfaces"....

or got another idea take one "route print" of one working PC + the wireless and post it here


Author Comment

ID: 9771656
No obvious changes in routing table...


As I was getting desperate, I just disabled WEP and prepared myself to (spend a lot of time on boring setups to) get the LAN back on 192.168.0 just like when everything was working fine. And to my suprise it worked!!!

I turned WEP back on, and it worked again!!! So now that last PC has an ethernet at and a wifi at and everything works fine, just like a few days ago. I don't have any expanation.

Any ideas or speculations on this are very welcome. I will be back soon with another question on routing, since the fact of two interfaces on the same subnet on the same PC can cause some confusion. I had posted a Q on this several months ago, but the answer turned out to be 'unsatisfactory'.

I hope you do not object on qwaletee getting the points.
LVL 31

Expert Comment

ID: 9773137
Eek, I didn't think of a bad WEP key.  Wheer did you turn it off/on?  The router, the PC, or both?

Aso, D-Link often has some issues with 128 bit encrption in early firmware versions, which can cause often cause the AP to seize up until WEP is reset.  Getting a firmwar upgrade often solves this.

Author Comment

ID: 9773523
The thing is that it was NOT a bad wep key! Otherwise it wouldn't connect at all. But as I said, I had a 100% link at all times! Hence my surprise.

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