I got a Buffalo router with native DD-WRT firmware. I updated the firmware, and it did install, and I was able to log in and use the settings.
Now, for reasons completely unknown, 3 different laptops using 2 different cable (and I know for a fact that one of the cables is good) can’t get the login page via ethernet cable.
I’m just out of ideas, and Buffalo pointedly refuses to help.
I’m open to any suggestions of what might be wrong. Ideas?
Are you getting an IP address?
Can you Ping the router?
How are you trying to access the login page? Via a browser with something like http://192.168.1.1 as the address? Do you get a login prompt? What model router is it? Which version of firmware did you update it to?
ETA: normally if a router gives me very much trouble, I’ll perform a hard reset and use the defaults to login (typically obtainable via a download of the specific model’s user’s guide from the manufacturer’s website).
Following up on beowulff’s comments. Can you get to the Internet? During your adventures with settings, did you perchance disable management access?
This is connected via ethernet while the computer is also able to get on the house wifi. I know the address is 198.162.11.1. I used it 3 other times. All I get is a timeout in the browser, even changing computers and cables. It’s a Buffalo WZR-300NH2. I don’t think I disabled management access. I never bothered with https one way or the other, before.
I updated it either with wzr-hp-g300nh2-dd-wrt-webupgrade-MULTI.bin or buffalo_to_ddwrt_webflash-MULTI.bin.
I can look up how to ping a router, but I don’t have any expectations, because nothing at all happens when I use the numerical address. The light on the ethernet port doesn’t even blink. We don’t know of it being dropped or mutilated.
Because you changed it to that? That doesn’t look like a default router gateway address (typically. 192.168.1.1 or 10.0.0.1).
Missed that.
I hope the OP just transposed the 2 and the 8, or he’s got problems…
I just typed it wrong here. Jeeeezt. Here it is copied from the actual browser address bar: http://192.168.11.1/
Since we have beowulff here, can I just quickly piggy back on this, as I have a similar question, specifically OS X related?
My desktop has an ethernet connection to the router (some Xfinity provided Motorola router/cable modem combo, which I will eventually replace with my own.) Sometimes, the computer simply doesn’t see it, so I have to switch to the wireless connection, which works fine. When I go to “System Preferences -> Network,” the ethernet connection simply shows up as “not connected” and I can’t seem to find a way to force a connection. The cable is plugged in fine, and usually doing a reset of the computer will solve the issue. But, otherwise, if the computer isn’t seeing the ethernet connection for some reason, I can’t seem to force it. I’ve tried unplugging and replugging the cable, but the only thing I can do is either switch to the wireless connection or restart the computer.
Any ideas what the problem can be? I know it’s a bit vague, but that’s as best as I can express it.
OK, that appears to be a valid gateway for a Buffalo router according to the site I linked.
Just trying to help!
I haven’t seen this exact problem before, but it sounds like doing an SMC reset might fix it.
It also might be worth a try to delete the Ethernet connection (click the ‘-‘ sign when it’s selected), and then re-adding it.
How often does this happen?
Oh, yeah, I’ve tried the remove and add connection to no avail in the past. As to how often it happens. I guess every few days or so? It’s hard for me to guage, as once my ethernet connection drop, I just stick it back to my wireless connection and just use it until I really need the ethernet speed again (to transfer gigs of files between this desktop and another one in the basement.) Yeah, I guess I should have also tried the usual SMC reset troubleshooting procedures. I was just wondering if there was something else obvious I may have missed. And it would help if I could figure out a consistent pattern as to when the ethernet drops – it doesn’t seem to be while I’m working at the computer, but rather after it’s been asleep. It seems like sometimes when I log in in the morning, I get the “No Internet Connection” error and then I just switch it over to the wireless and forget about it for awhile.
OK, looks like I managed to go 11 days without it being a problem. When the computer woke from sleep this morning, there was no ethernet connection. Says “Status: Cable unplugged; either the cable for Ethernet1 is not plugged in or the device at the other end is not responding.” Given that my cable is plugged in, I’m guessing option 2 is the problem, though I don’t know how to force it to respond.
So now I’m back onto wireless. I’ll do the SMC reset and see if that keeps the internet from going out for a longer period of time.
ETA: OK, restarted it; SMC reset, and computer seems to be back online via Ethernet. Let’s see if this lasts.
The new firmware you installed could have a bug.
Or the older firmware you updated over could have had a well-known bug, and the drivers you’re using could have been written to work around that bug, so that your computer is expecting the buggy behaviour - and doesn’t know how to deal with the correct behaviour of the updated firmware. 
If this keeps happening but it’s something that is corrected by a reboot or whatever, then you decide whether you want to mess with more things, or just keep on rebooting when it happens.
OK, there it went again today this morning. Restart fixed it. So it seems like about every two weeks when I go to wake the computer from its slumber, the ethernet disappears. Not really a big problem, since restarting always seems to solve the problem, but it’s gnawing at me not to be able to figure out what is going on.
I just upgraded my Buffalo WZR600 with the newest version of DD-WRT and it’s doing the same thing. My suspicion is that it’s having issues with my main router which is a Netgear but since I’m replacing that shortly we’ll see if I have any success.