2 Laptops, only 1 can be on WAP at a time

[Ike Turner]

Hello all,
I have been having a problem for a while now. Basically I have 2
WAPs set up at my house (on non overlapping channels). One is a DLink
and the other is a Linksys. Both are set to be in Mixed mode b/g
(though we have tried G only), and both are using WPA PSK. We have 3
Laptops, all of which are Dell 700Ms with the Intel A/B/G Card. They
are all also running Windows XP with SP2.

Here is the problem though, only 1 Laptop can be connected to a given
WAP at any one time. Once a second Laptop connects to the WAP, the
first one becomes disconnected until the user forces it to connect back
to the WAP, which then disconnects the other user. So basically it is
Last one in wins, and the other person just get disconnected. This
happens on both of the WAPs. I have tried using different software to
control the conection (Windows software and the Intel software). We
have tried different security types (WEP or WPA). I have tried other
things as well. I have searched and searched, but still have no answer
for this problem. Perhaps someone else has some ideas.

Ike
(e-mail address removed)

 

[w_tom]

IP addresses for each computer are? Are they set
statically or using DHCP?

Meanwhile Dell comes with a WLAN Card Utility that shows
Signal Strength in dBm. What does this utility report for
each machine when run independently AND when others attempt to
connect?

 

[Ike Turner]

The Laptops have been tried using both Static and DHCP. There are
enough addresses in the Pool. I will try the Signal Strength meter
later and respond with those results.

Ike

 

[STP.NET]

Here are two possible solutions:

1) your DHCP or router ran out of IP numbers
2) both wireless card have the same MAC address

 

[Ike Turner]

THere are still plenty of IPs left, anf the problem occurs with static
IPs as well. I checked the MAC addresses, and they are different, or
at least the last 4 digits are.

Ike

 

[Ben Myers]

NO Ethenet cards can have the same MAC address. Or maybe I should say that it
is wildly improbable. MAC addresses are assigned to cards in the late stages of
manufacturing from a pool of numbers from which the manufacturer can do the
assigning. Only a serious glitch in manufacturing can cause two cards to have
the same MAXC address.

But, yes, whichever entity in the network does IP address assignment may not be
set up correctly. A too-narrow range of IP address assignments could explain
what is happening.

However, I am not the only one who cannot construct a diagram of the network
boxes used by the OP... Ben Myers

 

[Ike Turner]

First of all the 2 Cable Modems thing. There are approx 12 computers
in our Living Room, and we all like to game and download, so if we all
shared one modem, it would get clogged up, and that would reduce our
online performance. That is why we have 2 Modems.


I see what you are saying about the routers. There are actually 3
routers so to speak.
There is the Cisco Router (7200 Series I think) that has an internal IP

of 192.168.1.128, and an external connection to Cable Modem 1.


There is the Solaris Box (I called it Linux earlier, but I forgot the
Linux box died) that has an internal IP or 192.168.1.1 and an external
connection to Cable Modem 2.


Determining which Cable modem a PC uses is determined by what IP they
use as their gateway. Otherwise all systems within the internal
network have 192.168.1.x IP addresses, assigned either statically or
through DHCP. The DHCP server has a 50 IP pool at the top of the range

that is not in use by any of the statically assigned PCs.


Both of the above router devices are connected into a Cisco Managed
Switch. VLANs are not actually being used on the device at this time,
though the ability is there, so that could have something to do with
the problem.

From the Cisco Switch, all other PCs are plugged directly into it with

IPs in the 192.168.1.x range. In addition to all PCs, there are the 2
Wireless devices:


The Linksys WRT54G (essid = BobbieBrown) that is running on channel 1
with WPA PSA TKIP enabled in mixed b/g mode.


The DLink DI-514 (essid=MikeTyson) that is running on channel 6 with
WPA PSA TKIP enabled in mixed b/g mode. This device is a router
(unfortunately), The WAN interface of the device is set to a
192.168.1.x IP address, and the LAN interface of the device is set to
192.168.2.1 and is a DHCP server giving out 192.168.2.x IP address.


Just to reiterate, the chief problem is the Laptops disconnecting from
the WAPs. All 3 Laptops are running Windows XP (2 Home, 1 Pro) and all

3 have the Intel 2915 ABG wireless card. Disconnects occur whenever a

second Laptop connects to an already in use WAP device. It occurs with

both the DLink and the Linksys. I think the issue is somewhere in the
settings on the laptops. Though it could be somewhere else.


I would tend to rule out the Cisco Switch as the DLink Router should be

reporting 1 IP address back to the Switch regardless of how many
devices are connected to it. Also, the disconnect is actually from the

WAP, and not from the switch. When one device associates with the WAP,

the other device physically disconnects from the WAP. So the problem
seems to be somewhere between the WAPs and the Laptops, and not in the
rest of our Network design/setup.


The reason I am using two WAPs is completely because of this problem.
If I could get 2 or 3 of the Laptops connected to a WAP simultaneously
I would remove the DLink device from the network completely. This
problem was occurring when it was just the Linksys, and the DLink was
just a fix (sort of) for that.


Thanks in advance.


Ike