LJ Brain Trust question
Jun. 22nd, 2003 01:59 pm![[personal profile]](https://www.dreamwidth.org/img/silk/identity/user.png){kind=small}
fishsupremeUpdate: Solved the problem. See inside the cut if you're interested...
I've spent the morning trying to solve a network issue, and I haven't been able to get anywhere. So, for any network geeks on my friends list, I have the following issue...
I have five computers on my network, and all are set to be in the same workgroup ("FLOCK"). On four of them, I can see those four machines; on the fifth, I can see only the computer I'm at. Basically, it seems I have two workgroups, with the same name -- one of four computers, and one of one.
The offending machine ("FISHSUPREME") is a Windows XP Pro machine. The network consists of:
Fishsupreme, a Windows XP Pro machine hooked to the switch
Dorset, a Windows XP Pro machine hooked to the switch
Shepherd, a Windows 2000 Server hooked to the switch
a Netgear ME301 wireless access point hooked to the switch
Merino, a Windows XP Pro machine on wireless to the access point
Cheviot, a Windows 2000 Pro machine on wireless to the access point
All machines get their IPs via DHCP from a DSL modem hooked to the switch. All are running ZoneAlarm Pro, though disabling ZAPro has no effect on the problem I'm seeing.
Now, the details of the problem are as follows. If I'm on Fishsupreme, \\shepherd\c$ does not work, but \\aaa.bbb.ccc.ddd\c$ (where aaa.bbb.ccc.ddd is the IP address for Shepherd) works. Likewise, if I'm on Shepherd (or any of the other three machines), \\fishsupreme\c$ does not work ("network connection could not be found"), while \\www.xxx.yyy.zzz\c$ (where www.xxx.yyy.zzz is the IP address for Shepherd) works.
From this I would think that NetBIOS over TCP/IP is not properly configured on Fishsupreme. However, I've done the following:
* Made sure all machines on the network had File and Print Sharing and Client for Microsoft bound exclusively to TCP/IP
* Made sure all machines on the network had Enable NetBIOS over TCP/IP turned on
* Reset the TCP/IP stack on Fishsupreme, restoring all registry settings to factory defaults
* Uninstalled and reinstalled the network on Fishsupreme, even reinstalling the network card with an updated driver
* Changed Fishsupreme's computer name
* Ensured the Computer Browser, Server, and Workstation services were all running on Fishsupreme
* Made sure all machines had appropriate IP addresses and subnet masks
* Power-cycled pretty much everything with a power button
I don't know what else to try. In addition, there's one other problem -- if I do connect to another machine via SMB (by doing \\www.xxx.yyy.zzz\c$ and using an IP address), I get a peak transfer rate of 0.1 Mbps. This is considerably below what I was getting before -- about 44.5 Mbps on the 100Base-TX network. In fact, it's below what I get off the Internet -- I can get 0.77 Mbps from web sites, yet only 0.10 from systems on the same switch! This really seems to me like two different, unconnected problems (since the first just looks like a NetBIOS name resolution issue, while this is a much broader problem -- if it weren't an entirely switched network, I'd think I was getting collisions.)
Any ideas?
Update: it appears my network traffic from Fishsupreme is actually getting routed out of our house! If I do a tracert from any of the 4 working machines to any of the others, it is, as you'd expect, one hop. However, a tracert to or from Fishsupreme actually goes out to the Verizon DSL gateway then comes back into the local subnet! Somehow I'm not thought to be on the same subnet as the other machines. Could this be a problem with DHCP, or our Linksys ethernet switch, or the DSL modem?
Updated Update: well, it looks like it's all Verizon's fault. My IP address is x.x.128.x, while the other computers in the house have x.x.148.x, x.x.153.x, x.x.156.x, and x.x.158.x IP addresses. All these are Verizon's DHCP-server-assigned IP addresses. The problem is that our subnet mask is 255.255.240.0 -- which means that my third octet of 128 puts me in a different subnet than machines with a third octet of 148, 153, 156, or 158. Our subnet mask means the subnet ID is the most significant 20 bits -- and my 20th bit is different from the rest of the house's 20th bit. Unfortunately, I don't think there's much of anything I can do about this -- and it's a major impediment to things like online games, since my traffic gets routed out of the house to communicate with other computers here, not to mention that 0.1 Mbps is not an acceptable transfer rate for a 100Base-TX network. Verizon doesn't even offer static IPs, the bastards. Any idea if there's something I can do about this?
Last Update: I called Verizon, and they acknowledged that their subnet mask is wrong, and that they do not care. They suggested I just release my IP "for 5 minutes" and get a new one. This does not seem a very good solution, as I've had the same IP address for 18 months now -- apparently it'll reserve your IP for your MAC address unless it runs out of new IPs when someone else signs in. Which means I might have to leave my computer turned off for weeks or months to get the address to reset -- not acceptable. But then I realized that if all I need is to have a MAC address with no reserved IP, I could just buy a new network card and slap it in, and that would give me a new IP -- but I'd have no guarantee it'd be any more valid than the one I already had! This would be irritating since new network cards cost money. But this led me to a better idea -- I could just hack the MAC address of my current card so that Verizon would think that my computer had never connected before, and would give me a new IP. And so I did this, and after cycling to new MAC addresses a couple times, I got an IP on the same subnet as all the other computers -- problem solved. Now, admittedly, I may be using someone else's MAC address now, so it's possible that I'll get an IP collision with them. But if so, I'll solve that problem another day. And considering as the programmable part of MAC addresses are 48-bit numbers, I think the chances of a collision are so infinitessimal as to not be worth worrying about. The lame part is that I just spent half my weekend troubleshooting Verizon's bad configuration, but at least my computer works now. Now to reprogram all the firewalls to trust my new IP...
I've spent the morning trying to solve a network issue, and I haven't been able to get anywhere. So, for any network geeks on my friends list, I have the following issue...
I have five computers on my network, and all are set to be in the same workgroup ("FLOCK"). On four of them, I can see those four machines; on the fifth, I can see only the computer I'm at. Basically, it seems I have two workgroups, with the same name -- one of four computers, and one of one.
The offending machine ("FISHSUPREME") is a Windows XP Pro machine. The network consists of:
Fishsupreme, a Windows XP Pro machine hooked to the switch
Dorset, a Windows XP Pro machine hooked to the switch
Shepherd, a Windows 2000 Server hooked to the switch
a Netgear ME301 wireless access point hooked to the switch
Merino, a Windows XP Pro machine on wireless to the access point
Cheviot, a Windows 2000 Pro machine on wireless to the access point
All machines get their IPs via DHCP from a DSL modem hooked to the switch. All are running ZoneAlarm Pro, though disabling ZAPro has no effect on the problem I'm seeing.
Now, the details of the problem are as follows. If I'm on Fishsupreme, \\shepherd\c$ does not work, but \\aaa.bbb.ccc.ddd\c$ (where aaa.bbb.ccc.ddd is the IP address for Shepherd) works. Likewise, if I'm on Shepherd (or any of the other three machines), \\fishsupreme\c$ does not work ("network connection could not be found"), while \\www.xxx.yyy.zzz\c$ (where www.xxx.yyy.zzz is the IP address for Shepherd) works.
From this I would think that NetBIOS over TCP/IP is not properly configured on Fishsupreme. However, I've done the following:
* Made sure all machines on the network had File and Print Sharing and Client for Microsoft bound exclusively to TCP/IP
* Made sure all machines on the network had Enable NetBIOS over TCP/IP turned on
* Reset the TCP/IP stack on Fishsupreme, restoring all registry settings to factory defaults
* Uninstalled and reinstalled the network on Fishsupreme, even reinstalling the network card with an updated driver
* Changed Fishsupreme's computer name
* Ensured the Computer Browser, Server, and Workstation services were all running on Fishsupreme
* Made sure all machines had appropriate IP addresses and subnet masks
* Power-cycled pretty much everything with a power button
I don't know what else to try. In addition, there's one other problem -- if I do connect to another machine via SMB (by doing \\www.xxx.yyy.zzz\c$ and using an IP address), I get a peak transfer rate of 0.1 Mbps. This is considerably below what I was getting before -- about 44.5 Mbps on the 100Base-TX network. In fact, it's below what I get off the Internet -- I can get 0.77 Mbps from web sites, yet only 0.10 from systems on the same switch! This really seems to me like two different, unconnected problems (since the first just looks like a NetBIOS name resolution issue, while this is a much broader problem -- if it weren't an entirely switched network, I'd think I was getting collisions.)
Any ideas?
Update: it appears my network traffic from Fishsupreme is actually getting routed out of our house! If I do a tracert from any of the 4 working machines to any of the others, it is, as you'd expect, one hop. However, a tracert to or from Fishsupreme actually goes out to the Verizon DSL gateway then comes back into the local subnet! Somehow I'm not thought to be on the same subnet as the other machines. Could this be a problem with DHCP, or our Linksys ethernet switch, or the DSL modem?
Updated Update: well, it looks like it's all Verizon's fault. My IP address is x.x.128.x, while the other computers in the house have x.x.148.x, x.x.153.x, x.x.156.x, and x.x.158.x IP addresses. All these are Verizon's DHCP-server-assigned IP addresses. The problem is that our subnet mask is 255.255.240.0 -- which means that my third octet of 128 puts me in a different subnet than machines with a third octet of 148, 153, 156, or 158. Our subnet mask means the subnet ID is the most significant 20 bits -- and my 20th bit is different from the rest of the house's 20th bit. Unfortunately, I don't think there's much of anything I can do about this -- and it's a major impediment to things like online games, since my traffic gets routed out of the house to communicate with other computers here, not to mention that 0.1 Mbps is not an acceptable transfer rate for a 100Base-TX network. Verizon doesn't even offer static IPs, the bastards. Any idea if there's something I can do about this?
Last Update: I called Verizon, and they acknowledged that their subnet mask is wrong, and that they do not care. They suggested I just release my IP "for 5 minutes" and get a new one. This does not seem a very good solution, as I've had the same IP address for 18 months now -- apparently it'll reserve your IP for your MAC address unless it runs out of new IPs when someone else signs in. Which means I might have to leave my computer turned off for weeks or months to get the address to reset -- not acceptable. But then I realized that if all I need is to have a MAC address with no reserved IP, I could just buy a new network card and slap it in, and that would give me a new IP -- but I'd have no guarantee it'd be any more valid than the one I already had! This would be irritating since new network cards cost money. But this led me to a better idea -- I could just hack the MAC address of my current card so that Verizon would think that my computer had never connected before, and would give me a new IP. And so I did this, and after cycling to new MAC addresses a couple times, I got an IP on the same subnet as all the other computers -- problem solved. Now, admittedly, I may be using someone else's MAC address now, so it's possible that I'll get an IP collision with them. But if so, I'll solve that problem another day. And considering as the programmable part of MAC addresses are 48-bit numbers, I think the chances of a collision are so infinitessimal as to not be worth worrying about. The lame part is that I just spent half my weekend troubleshooting Verizon's bad configuration, but at least my computer works now. Now to reprogram all the firewalls to trust my new IP...
