Strange DHCP behavior with 374.43 firmware

[Cromm]

Hi,

I just flipped over from the stock firmware on a RT-N66U to Merlin's build. One of our laptops is fine but the second one is exhibiting some strange behaviour on it's DHCP requests.

My wife complained she couldn't get onto the Internet, when I checked her laptop had been given a 192.168.100.x address, but our DHCP range is 192.168.0.100-115.

I was figuring some sort of malware or a some crazy locally installed DHCP server. But that wasn't the case at least what I could find.

If I set a reservation on the router she would get the specified IP. When I was going through the Logs I came across the following in the DHCP sequence.

Jul 4 18:32:01 dnsmasq-dhcp[511]: DHCPDISCOVER(br0) 80:56:f2:82:64:ad
Jul 4 18:32:01 dnsmasq-dhcp[511]: DHCPOFFER(br0) 192.168.0.113 80:56:f2:82:64:ad
Jul 4 18:32:01 dnsmasq-dhcp[511]: DHCPREQUEST(br0) 192.168.100.17 80:56:f2:82:64:ad
Jul 4 18:32:01 dnsmasq-dhcp[511]: DHCPNAK(br0) 192.168.100.17 80:56:f2:82:64:ad wrong server-ID

any help would be great

thanks

 

[ColinTaylor]

http://www.smallnetbuilder.com/forums/showthread.php?t=16548

The message indicates that the laptop has recently been connected to another network. Perhaps at work or a public Wi-Fi hotspot?

 

[Cromm]

That's the same problem I'm having but it's affecting everything internally, even items like my Chromecast that never connect to another network. I'm got no idea how or why this started.

 

[ColinTaylor]

I understood from your original post that it was only effecting one laptop. Now you say it's effecting everything on your network?

In which case there must be another DHCP server on your network. How are you connecting to your ISP? Maybe you're picking up their DHCP server.