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TomTierney

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Strange IP Addresses being picked up

The last few days , a number of our desktops have acquired strange IP addresses , outside our range . They pick up an address in the range 192.168.11.xx . To reset I have to go into CMD and ipconfig /release then ipconfig/renew . Is there any way this can be prevented ?
All help gratefully received .

regards ,
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John-Charles-Herzberg
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Have you scanned you network for another DHCP server?

Thanks
JC
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IanTh
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TomTierney

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How can I fix it ??
This software might help.

DhcpExplorer allows you to discover DHCP servers on your local subnet or LAN

http://www.softpedia.com/get/Network-Tools/Network-IP-Scanner/DHCPExplorer.shtml
This video might help if you are OK with using linix to help find the DHCP server(s)

3hacks : Rogue DHCP Server Detection (dhcp_probe)

http://www.youtube.com/watch?v=bc1m4Npoyik

Thanks
JC
Still got the problem . Downloaded DHcP explorer but that only shows our subnet . I viewed the video but didn't 'get it' . I can see no visible signs of a 'home' address so difficult to remove . I really am struggling with this one . Anyone ?
can yu ping the rogue ip addres I mean does it actually exist
I tried pinging one of the addresses I have seen and it just timed out .... 192.168.11.11
Our RAS server has an address of 192.168.11.14 ?? I don't recall this . Does this sound correct ?
whats your lan ip address range ? 10.0.0.x or someting
192.168.16.x
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I've requested that this question be closed as follows:

Accepted answer: 0 points for TomTierney's comment #37747205

for the following reason:

It appears to have done the trick . It would appear to be a common occurrence .<br /><br />regards ,
I would like to point to my second post where I stated

as 192.168.x.x is a home ip range I bet somebody has put their home router with dhcp running onto your lan imho

and your cooment

Hi , it appears that my problem was caused by a Buffalo router that we have deployed at one of our satellite sites . We spotted this on a tech forum and now , having disabled this equipment , normality has been restored

how is that different I stated it was another router and your fix is another router
thanks