Networks·41,424 discussions

Wrong WLAN IP

Locked

In our netword we have two accespoint, one is for our visitors (AP6) with ip-range 192.168.6.xxx and the other one (AP2) for own network 192.168.2.xxx.

Got this problem with one user, running XP Pro SP3, when he connects with AP2 he gets an 192.168.6.xxx ip instead of a 192.168.2.xxx.

Network is as follow configured:
192.168.6.xxx receive ip from router (DHCP)
192.168.2.xxx receive ip from a windows 2003 DHCP server.

What could be the problem?

Topic

Clarifications

In reply to Wrong WLAN IP

Clarifications

Silly question

In reply to Wrong WLAN IP

But have you configured the wireless box to use this IP range?

Yep

In reply to Silly question

Everything works gr8, only with this user have this problem.

I also tried ipconfig /release and then /renew. Disabling and Enable WLAN connections.
He connects on AP2 but he gets ip 192.168.6.xxx from AP6.

And one strange thing, if i add a static ip with 192.168.2.xxx , he can acces our network

Scope(?)

In reply to Yep

This is a long shot, but is the DHCP scope on AP2 full? Can you disable the DHCP passthru on that ap? maybe you have already looked, but I would;

1. Check both APS to see if the IP shows up in the DHCP lease table.

2. Check AP2 and see if there is an additional scope in the AP6 range

3. Physically shut down the APS individually then together to see if the client still connects. (just wondering if there are APs 3-5)

4. Clear the entries for the wan and lan connections on the client and make sure there are no static entries in the IP settings for any connection including the alternate connections.

Hope this helps.

Even Sillier question

In reply to Wrong WLAN IP

How are you verifying which access point it is connecting to? and is there any rule or setting to limit access to either the internal or external user access points?

By the SSID

In reply to Even Sillier question

evevery AP have a different SSID with different key.

There’s no rule, if you mean like mac-rules.
They are just simple AP, one is a router which releases ip 192.168.6.xxx and the other one is a AP, which is connected to our network.

Sillier again

In reply to By the SSID

How are you going about this, you would need another line to host the wireless which will not be internal to your network, I don’t think an extra subnet is any good for you?

More info

In reply to By the SSID

I got some more info, maybe wil confuse you more. But i will answer all you “silly” question if needed.

We have two internet connection from different providers. Both connections are managed by a Sonicwall 2040 Pro.

There’s an acces rule in the firewall wich 192.168.6.xxx can’t access 192.168.2.xxx in neither way.

BUT there’s only one configuration based on IP that permits some user’s to access AP6 router to use it as a gateway to the internet.

Configuration

In reply to More info

To be sure I would again check the wireless configuration for that box, you may have misconfigured it easy done, if configuration is correct install something called wireshark on the machine and look at how it’s communication with network this will hope you resolve problem.

Ok…

In reply to Configuration

I’ll try your suggestions.

But this is still strange for me, since this only happens with one PC, we have different PC’s and other mobile devices (iPhone,Android,WM) and no one has this problem.

The user connects on AP2 and he gets ip from AP6.

But anyways i’ll try anything

Best to look

In reply to Ok…

Onto it then, maybe also add that mac to the blocked list in mac filtering if your worried this user will gain access to the network, also test with another laptop in case your network is open to attacks because of this problem just a thought 🙂

what your describing really isn’t possible

In reply to Wrong WLAN IP

There’s no way for a client connecting to an access point on one subnet to obtain an address from a DHCP server on a different subnet unless the DHCP server has a relay agent running. You don’t mention this in your posts.

isn’t it possible if

In reply to what your describing really isn’t possible

The wireless access point is allowing dhcp pas through (relay) and for some reason it’s DHCP scope is full?

Touching on an earlier point, assuming it isn’t an issue with the client( I know, bug assumption) isn’t there a larger issue concerning one’s ability to enumerate resources on the network? Unless that segment is limited, it seems like there is a huge hole there.

as I mentioned earlier only with the relay agent running

In reply to isn’t it possible if

this is different subnets [addressing] so an access point on one subnet with a specific address on that subnet allows a connection just like wired allows a connection. To obtain an address dynamically, there has to be a DHCP server to provide them. That also is on the same subnet. Can’t have 2 DHCP servers on the same subnet, [unless using superscopes].

So how can a host connect to a network on one subnet and obtain an address on another subnet where there is a DHCP server handing out addresses on the subnet the host connects to? Even if the DHCP server ran out of addresses, the APIPA address would be assigned, not an address on a different subnet, unless there is a DHCP relay agent running.

Update

In reply to Wrong WLAN IP

Hey Thnx for your answers and suggestions.

I noticed that also wired workstation are getting ip from the router.So this is not only an issue with wireless.

I ask SW for support if they can help me out with this issue.

If anyone can help me with how to trace a relay agent on a network I will be very thankfull

Solved!

In reply to Update

After checking our Network i finally found the problem.

We got a loop which bypasses the Sonicwall and releasing it’s own IP’s on the local network.

“Someone” connected a cable from the DHCP router to our network. Ofcourse no one didn’t do it.

Thanks for all your replies!

well yep that would do it…so no one would own up eh?

In reply to Solved!

.

[Author]

Replies