A few weeks ago I switched from fiber to cable. My router switched as well. The only settings that are really different is the address mask. The router is 10.0.0.1 instead of 192.168.1.1, and the new DHCP pool is from 10.0.0.4 to 10.0.0.253. The problem is, that since then I haven't been able to get my wireless card in one machine to work. The rest are fine. Now I know what you are thinking. Obviously, it has something to do with the router. The problem is. I don't see anything wrong with it.
Indecently the one machine is a laptop which seems to work everywhere else. However, in the past month or so. download speeds have drastically decreased. For example a file that should be a 10 minute download comes up as 19 hours.
here's what I have tried so far. without changing anything the laptop see's the network and when I ask it to connect, it does. ifconfig shows that it is assigned a valid IP. When I log at the log files in the router it shows the dhcp request but don't show record or my machine connecting or having ever connected to the network.
Occasionally I can ping the router, with horrible latency. bit even that is rare.
I have an external usb card. Works, as long as I bring down the other device with ifconfig, but still very slow. Speedtest.net rates it at 3.49 mbps down 4.05 up. My computer connected to the router gets 52.9 mbps down and 10.7 up.
to me it kinda sounds like a software problem, but I'm not really sure what to check. Any suggestions?
Also, this is probably just a coincidence but a couple weeks before I started noticing slow speeds I switched from Gentoo to Ubuntu.
I don't see what that would change anything, but I just figured I'd mention it.
some of these may help
lsusb (the RTL8187 is the usb card that still works slowly)