multiple DHCP servers on network with Linksys BEFW11S4?

[gmoney007]

Hi All,

A question for the networking gurus out there...

The higher-ups at my office decided they needed a wireless access point so they could play internet hearts in the conference room during "bored meetings." I bought a Linksys BEFW11S4 and 2 cards for them to play with, and stuck it on the network.

We currently have an NT 4.0 box on the network acting as a DHCP server. We assigned the BEFW11S4 a static IP address on our network, and configured that to act as a DHCP server. The BEFW11S4 is currently only talking to 2 wireless laptops that used to be wired and assigned IP addresses by the NT 4.0 DHCP box. We encountered a couple of problems:

1) We were originally thinking that the BEFW11S4 could use a static IP and act as a DHCP to just the wireless clients without using "real" IP addresses. In other words, letting the BEFW11S4 "share" an IP address in much the same way it would allow a cable modem connection to be shared. This simply didn't work, as there was no connectivity to the rest of our network through the BEFW11S4 when configured this way. We had to change the BEFW11S4 so that it was *not* acting as a DHCP, but as a simple WAP, and the wireless clients were getting IPs from the NT 4.0 DHCP server. OK, no problem. However:

2) For some reason, the wireless clients are grabbing IPs from the DHCP server like crazy! One (wired) office member couldn't get on the network, and a quick check revealed that one of the wireless clients had claimed NINE separate IP addresses in about 15 minutes, and the other had claimed 3 separate IP addresses in about the same time. This used up all of our dynamic IPs. I checked through the settings on both the BEFW11S4 and NT 4.0 server, and didn't see any obvious way to limit the number of IPs taken by a given computer.

Any ideas on problem 1 or 2? I tried a maddening number of setting changes on both the BEFW11S4 and NT 4.0 box after that, and nothing has changed.

Thanks for any help!

 

[denpgeorge]

are the laptops coming in and out of signal from the access point? if so i think maybe thats why they keep requesting a new address... would the same thing happen to the dhcp server if you kept unplugging and plugging a wired computer? if this is the case, maybe you should set the laptops up with static address as well.

hope it helps.

 

[gmoney007]

Hey denpgeorge,

No, the laptops were not coming into and out of range with the WAP. I had all three units on the same table in the same room, and there was no indication of dropped signals between either laptop and the WAP.

Unplugging and plugging in wired computers is something to try, though. I hadn't thought of that. It would be a good test for determining the cause of those pesky multiple leases.

Any other thoughts? Anybody?

 

[PlatinumGold]

gmoney

you have a lan cable going from you current network to the Linksys wap correct?? did you plug that into the WAN Port??

Your better off doing what you wanted to do orginally, have the WAP serve as a NAT box and assign it's own internal IP addresses to the two wireless NIC's.

Now, when you had the Linksys set up as a NAT box what was and wasn't working??

 

[gmoney007]

Hi PlatinumGold,

Yes, I used a regular CAT5 cable (not a patch) to connect the Linksys to an existing wall LAN plug. I plugged that cable into the WAN Port, and nothing worked. My coworker told me I had to plug it into the Uplink port, so I also tried that. That also failed with the Linksys set up as a DHCP. I chose the wall socket because it was unused and in the conference room that we most wanted wireless access to.

When I had the Linksys set up as a NAT box, the wireless NIC's could communicate with the Linksys, but couldn't load web pages or see our intranet or anything. In other words, the link and activity lights were on on the Linksys, and the packet counters were increasing in the "Local Area Connection Status" window, but no local computers could be seen and IE6 said all of my favorite pages were not found.
I did the usual act of power cycling everything and rebooting computers, but none of this solved the problem.

Disabling the DHCP on the Linksys *and* moving the cable from WAN to Uplink allowed the wireless NIC's to see the NT 4.0 DHCP server, but that led to our runaway IP assignment problem.

If I want the WAP to serve as a NAT box, how would I do that? I was thinking that I should assign the WAP a static IP and then assign the wirless NIC's internal IP addresses, but it wasn't clear how to do that on the configuration page for the Linksys. Should I, instead, have the WAP get an IP from the NT 4.0 DHCP server on our network? Also, should this thing be plugged into the WAN Port or Uplink?? Does it change depending on how I configure the box internally?

Thanks!

 

[PlatinumGold]

gmoney,

first things first.

plug the cat 5 cable into the wan port. this particular WAP that ur using also has the ability to connect via cat 5 so use that to connect to any pc via cat 5. establish first of all that your getting a connection to the main network.

then you have to do the wireless settings. but i would first of all establish that your getting connectivity at all via a wired connection.

it seems to me that your problem could be your wireless settings.

 

[krystalogik]

try telling the Linksys to use a different set of ip's for it's DHCP clients?

ie, if the NT box is handing out 192.xxx.xxx.xxx addresses, have the linksys hand out 10.xxx.xxx.xxx addresses.

PM me if that helps.