RE: [expert] weird network problem
John, The problem is solved. We managed to get the hang of the ex-administrator (poor system documentation by him) and enquired about the system he left. The switch hub need to be configured so that's what we did. The Linux server is working fine now. Thanks for the checklist... It does help us a lot. Best Regards, Joe RLU# 186063 "Reading is the essence of knowledge" > -Original Message- > From: [EMAIL PROTECTED] > [mailto:[EMAIL PROTECTED]]On Behalf Of John Wolford > Sent: Friday, April 27, 2001 02:07 PM > To: Joe; Linux Expert List > Subject: Re: [expert] weird network problem > > > Joe, > > When you moved the linux server, did you carry the cables with > it? Plugged into a hub, you must > have used straight-through, but in the new location should it be > crossover, perhaps? Or maybe it > should be straight-through but for some reason it is crossover? > In other words, good cables but > bad physical configuration? > > Is it still on the same LAN, same network address? All sorts of > problems could be causing it, if > not. > > Is it plugging into a switch, or something that needs to be > reconfigured to allow access? > > Does it have to go through a firewall, or a router access control > list, that it didn't have to > before? > > If you pull another test box into the room with the server, and > you attatch a crossover cable > between them and set up the ip address properly (same network), > do you have connectivity? (If you > use a hub in between the two, you need straight-through, not > crossover). What i'm asking, is can > you get the server to connect with ANYTHING in that room, other > than plugging it into the > connection which is not currently working? > > Was anything getting configured from the server, which is now not > getting configured, and could > that thing be causing loss of connectivity? Like, say, a router? > I guess that would come back to > it being on a different network. > > Can the server still ping its own network card (specified by its > ip address, not by "localhost")? > If you can't then you can't ping anyone else either. Make sure > your network card is up. If it's > not, then maybe it gets its ip configuration from a DHCP server, > which it is not able to reach for > some reason (some physical-layer or layer-2 reason). > > Umi guess that's a mish-mash of suggestions: 1) physical > (crossover vs straight-through > cables; 2) "layer-2" (switches, MAC-based filters); "layer-3" > (routers, ip-based firewalls, > changed networks, changed gateway, ip address configuration > (static vs dhcp). > > If nothing makes sense, then start looking very closely at the > things you take for granted > (cables, this, that, whatever). Sometimes just thinking of the > things we take for granted and > forcing ourselves to not take them for granted is the hardest > part of trouble-shooting. > > Good luck, let us know any developments. It's fun stuff - for us > anyway :-) > j > > > --- Joe <[EMAIL PROTECTED]> wrote: > > Dear Linuxguys, > > > > We have a problem which we find rather weird. > > We have a Linux Server running our mail server in the office > (we have leased > > line). > > > > This particular server worked well in the other room (server > room1) but it > > does not work in another. To say that the cabling at the other room is > > faulty, it is not since we put other machines there and it > worked fine... we > > can ping, access the service and all. Even the Windows clients > worked there. > > > > Network card, we're sure nothing wrong with it too. > > > > But when I put the Linux server machine straight into the hub, > it worked. We > > can't leave the server near the hub though, as we don't have > anymore space. > > We have to put it somewhere else which apparently it does not > work elsewhere > > except the hub... unable to ping, unable to access the service and all. > > > > Can anybody give us a checklist on what should we check? > > > > By the way, we are running LM7.0 without X Server, no KDE, no GNOME etc. > > > > We appreciate your assistance in any kind. > > > > Thanks! > > > > Best Regards, > > > > Joe > > RLU# 186063 > > "Reading is the essence of knowledge" > > > > > > > > > > > __ > Do You Yahoo!? > Yahoo! Auctions - buy the things you want at great prices > http://auctions.yahoo.com/ >
Re: [expert] weird network problem
Joe, When you moved the linux server, did you carry the cables with it? Plugged into a hub, you must have used straight-through, but in the new location should it be crossover, perhaps? Or maybe it should be straight-through but for some reason it is crossover? In other words, good cables but bad physical configuration? Is it still on the same LAN, same network address? All sorts of problems could be causing it, if not. Is it plugging into a switch, or something that needs to be reconfigured to allow access? Does it have to go through a firewall, or a router access control list, that it didn't have to before? If you pull another test box into the room with the server, and you attatch a crossover cable between them and set up the ip address properly (same network), do you have connectivity? (If you use a hub in between the two, you need straight-through, not crossover). What i'm asking, is can you get the server to connect with ANYTHING in that room, other than plugging it into the connection which is not currently working? Was anything getting configured from the server, which is now not getting configured, and could that thing be causing loss of connectivity? Like, say, a router? I guess that would come back to it being on a different network. Can the server still ping its own network card (specified by its ip address, not by "localhost")? If you can't then you can't ping anyone else either. Make sure your network card is up. If it's not, then maybe it gets its ip configuration from a DHCP server, which it is not able to reach for some reason (some physical-layer or layer-2 reason). Umi guess that's a mish-mash of suggestions: 1) physical (crossover vs straight-through cables; 2) "layer-2" (switches, MAC-based filters); "layer-3" (routers, ip-based firewalls, changed networks, changed gateway, ip address configuration (static vs dhcp). If nothing makes sense, then start looking very closely at the things you take for granted (cables, this, that, whatever). Sometimes just thinking of the things we take for granted and forcing ourselves to not take them for granted is the hardest part of trouble-shooting. Good luck, let us know any developments. It's fun stuff - for us anyway :-) j --- Joe <[EMAIL PROTECTED]> wrote: > Dear Linuxguys, > > We have a problem which we find rather weird. > We have a Linux Server running our mail server in the office (we have leased > line). > > This particular server worked well in the other room (server room1) but it > does not work in another. To say that the cabling at the other room is > faulty, it is not since we put other machines there and it worked fine... we > can ping, access the service and all. Even the Windows clients worked there. > > Network card, we're sure nothing wrong with it too. > > But when I put the Linux server machine straight into the hub, it worked. We > can't leave the server near the hub though, as we don't have anymore space. > We have to put it somewhere else which apparently it does not work elsewhere > except the hub... unable to ping, unable to access the service and all. > > Can anybody give us a checklist on what should we check? > > By the way, we are running LM7.0 without X Server, no KDE, no GNOME etc. > > We appreciate your assistance in any kind. > > Thanks! > > Best Regards, > > Joe > RLU# 186063 > "Reading is the essence of knowledge" > > > > __ Do You Yahoo!? Yahoo! Auctions - buy the things you want at great prices http://auctions.yahoo.com/
[expert] weird network problem
Dear Linuxguys, We have a problem which we find rather weird. We have a Linux Server running our mail server in the office (we have leased line). This particular server worked well in the other room (server room1) but it does not work in another. To say that the cabling at the other room is faulty, it is not since we put other machines there and it worked fine... we can ping, access the service and all. Even the Windows clients worked there. Network card, we're sure nothing wrong with it too. But when I put the Linux server machine straight into the hub, it worked. We can't leave the server near the hub though, as we don't have anymore space. We have to put it somewhere else which apparently it does not work elsewhere except the hub... unable to ping, unable to access the service and all. Can anybody give us a checklist on what should we check? By the way, we are running LM7.0 without X Server, no KDE, no GNOME etc. We appreciate your assistance in any kind. Thanks! Best Regards, Joe RLU# 186063 "Reading is the essence of knowledge"
