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imz-ez

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IP Conflict Error

In my small office there is 1 DSL and 2 Wireless Routers are working. DHCP is configured only on DSL. 1 Cable is comming from DSL and connected to Wireless Router in LAN ports and 2nd cable coming from DSL and connected to 2nd Wireless Routers in LAN ports. DHCP is disabled on both wireless routers. Sometimes few computers got msg of IP Conflict. Please help me what should I do know. I want to use only 1 DHCP which is already configured on DSL. MAC Binding option is not available on DSL Router. There is no other server in our office. Please Help.
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James
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Do you have a Server in your Office? What is the DHCP Pool size on the Router that is doing DHCP?
You can also check on the Router what ip addresses are assigned to which client computers. Are any of your computers using Static IP Addresses that are not Reserved on your Router?
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Onlyodin

For the affected windows computers, run the following command from a Command Prompt (cmd.exe):

ipconfig /all

Listed under the network connections will be the DHCP settings, and listed should be the DHCP server.  

Check that the DHCP server is the same on all computers, if there is more than one DHCP server you could run into problems.

Also, if you have any computers, printers, devices (including the wireless AP's) with manual or static IP addresses, these need to be set outside the DHCP range to avoid possible conflicts.
Also, on the affected PCs from the command prompt type

ipconfig /release and press enter and then type ipconfig /renew and press enter.
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ASKER

Gentleman it was clearly written in my question that there is no dhcp server installed in our office and all laptops are getting IP from DHCP. Nobody is using static IP Address. Everything is mentioned in my question that dhcp is configured only on DSL
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ASKER

DHCP Pool size is 192.168.2.2 to 192.168.2.100. Only 20 Laptops are in our office.
The modem that your ISP Provided you with, is the firmware up to date on this?
What is on WAN ports of your WiFi routers? May be they can be set to Access point mode?
If there are "get address from DHCP" or static address from your network, try to set them manually to addresses out of your network (10.10.0.1 and 10.10.1.1, for example)
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ASKER

I m using Linksys wireless router Wireless-G Broadband Router WRT54GL. DHCP is disabled on both wireless routers.
As you have reiterated that you have no other DHCP servers, have you confirmed that your DSL router is definitely handing out duplicate IP addresses, by using the ipconfig /all command to verify the DHCP server address and lease duration information?

Do the duplicate IP address warnings coincide with anything else, for example, rebooting the DSL router or Wireless devices?

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ASKER

I have checked the dhcp command and the dhcp server address is correct and lease duration is also ok.  its not coincide with anything.
Do the wireless routers have a static ip?

If there is a conflict, did you check what ip address that was and what the two conflicting devices were?
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ASKER

yes wireless router have static IP Addres. ONe wireless router has IP 192.168.2.226 and other wireless router address is 192.168.2.227.
And did you try to figure out which devices are conflicting? Are they the same every time or is it random.

You also might want to check the firmware on your routers and DSL to see if they are the newest (if you haven't done so allready).
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ASKER

Its random and secodly Firemware is already updated
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thomasdietrich
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ASKER

How do I come to know my linksys router is acting as access point or gateway?
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ASKER

Mode is Gateway on both wireless routers. What should I do know?
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ASKER

Can u tel me what is MTU and on my routers mtu is auto. Should I set it manual and what should be ideal range?
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ASKER

It helped me alot. thanks
The MTU controls how large the packets are that are transmitted.  Auto is normally 1500, which is fine in just about every circumstance.  The only time I've ever adjusted the MTU was to step it down to 1492 to accomodate VPN traffic.  If you ever adjust it you step it down by values of 8.

Apparently you found the place to change it from Gateway to Router.

Good luck!
Tom