networking weirdness
Jul. 9th, 2002 09:16 pm![[personal profile]](https://www.dreamwidth.org/img/silk/identity/user.png){kind=small}
cellioEver since the power surge (and resulting replacement of Linksys box and one other hub), we have been noticing sporadic weirdness on our network. We use DHCP to hand out IP addresses (doesn't everybody?). The Linksys box is configured (by default, if I recall correctly) to start handing out addresses at 192.168.1.100. The Linksys itself is 192.168.1.1. As best I recall, these are the same settings we used successfully on its predecessor for close to three years.
So now, every now and then, it will hand out the address 192.168.1.2. And that unlucky machine will be able to see the LAN but not the internet. Rebooting usually does not fix it, but creative sequences of reboots of all machines and power-cycling of the modem and Linksys usually do the trick.
We cannot find any common factor when this happens. Sometimes it just does.
Tonight, when I found myself the unwilling owner of 192.168.1.2, I decided to try an experiment: I gave myself a fixed IP address without changing anything at the Linksys end. I guessed that I should use 192.168.1.1 for the gateway and name service, rather than the "real" ones; after all, the Linksys box is supposed to resolve the interface issues between the local machines and the network, right?
This worked perfectly. In fact, in a rare Windows moment, I didn't even have to reboot!
I assume that as the other machines encounter the wayward 192.168.1.2 we'll make this adjustment on them, too, until nobody's using DHCP any more. Then we'll forget about this until some unlucky house guest wants to plug his laptop into the network. :-)
I feel like this is an ugly hack. I have not solved the real problem. But at this point I think I'm going to stop looking for it.
Because there is a strict quota on hardware happiness, I found that the 4-port hub we had lying around is really only a 2-port hub. (One is "uplink", which seems to be magic and does not work with anything I tried to plug into it, and one is just dead.) So I can't get rid of the cables strung across the floor just yet.
So now, every now and then, it will hand out the address 192.168.1.2. And that unlucky machine will be able to see the LAN but not the internet. Rebooting usually does not fix it, but creative sequences of reboots of all machines and power-cycling of the modem and Linksys usually do the trick.
We cannot find any common factor when this happens. Sometimes it just does.
Tonight, when I found myself the unwilling owner of 192.168.1.2, I decided to try an experiment: I gave myself a fixed IP address without changing anything at the Linksys end. I guessed that I should use 192.168.1.1 for the gateway and name service, rather than the "real" ones; after all, the Linksys box is supposed to resolve the interface issues between the local machines and the network, right?
This worked perfectly. In fact, in a rare Windows moment, I didn't even have to reboot!
I assume that as the other machines encounter the wayward 192.168.1.2 we'll make this adjustment on them, too, until nobody's using DHCP any more. Then we'll forget about this until some unlucky house guest wants to plug his laptop into the network. :-)
I feel like this is an ugly hack. I have not solved the real problem. But at this point I think I'm going to stop looking for it.
Because there is a strict quota on hardware happiness, I found that the 4-port hub we had lying around is really only a 2-port hub. (One is "uplink", which seems to be magic and does not work with anything I tried to plug into it, and one is just dead.) So I can't get rid of the cables strung across the floor just yet.
(no subject)
Date: 2002-07-09 08:49 pm (UTC)You don't, by any chance, end up in situations where you have more than 20-ish different computers plugged into the network in a small timespan (say, a lan party or a social get-together with a bunch of laptopped geeks)? I could imagine really dumb software climbing to 192.168.1.126 then rolling over to 2.
(no subject)
Date: 2002-07-10 06:03 am (UTC)No, we've never had more than half a dozen machines connected. Currently our max is five. (One of those has only occasional presence on the net; it's the one that can't stay up for more than 20 minutes or so without overheating. I'm almost done recovering the stuff I need from that disk, and then it'll be time to attempt surgery.)
(In case you're wondering, yes I do backups, but backups sometimes have trouble with stuff in Windows or Program Files and I haven't generally worried about that. All the real data is safely backed up; I want to make sure I've captured things like the random program settings and dlls that are quietly stored away in less-than-obvious places.)