View Full Version : LAN Issue, realy annoying
I have had an ongoing issue at our office regarding the network.
Its the typical auto neg between the nic and switch.
Even though all nics connect properly to the switch at 100/full they dont transfer data very fast. I have tried forcing the 100/full on the swith and nic but still is slow. If its set to 100/half then all is well and the transfer speed tops out at abt 80% of line speed from server to client machine.
Now this is the real twist, the problem only realy exists when files are transfered between client and server, between client and client 100/full works fine.
The server is a ML370G4 with the nic forced to 1000/full also on the switch, OS SBS2003 (not my choice).
Any ideas much apreaciated. Its all working fine i would just like all the clients to speak 100/full to the switch and server.
If I have read what you say correctly - it sounds like the server NIC could be at fault?
fizzwheel
28-04-06, 09:45 AM
If I have read what you say correctly - it sounds like the server NIC could be at fault?
Thats where I would start. TSM have you got the latest drivers for the NIC installed. Also what sort of state are the patch cables in have you tried new ones ?
If I have read what you say correctly - it sounds like the server NIC could be at fault?
Thats where I would start. TSM have you got the latest drivers for the NIC installed. Also what sort of state are the patch cables in have you tried new ones ?
I updated all the drivers on the server in March, the
ProLiant Support Pack was dated Jan but there is a new one released just a few days ago. I will try that.
All the patch cables are in good nick but they have been the same ones in the patch for the last 5 years at least. Ive got new one in a box, i was going to try that later today when i get back to that office.
fizzwheel
28-04-06, 09:52 AM
The only other thing it could be is the port on the switch that the server is plugged into is faulty. Might be worth trying a different port as well ?
The only other thing it could be is the port on the switch that the server is plugged into is faulty. Might be worth trying a different port as well ?
I will try that, only 1 other 1000T port, if that does not work then i will try putting the server down to a 100T port to see what happens. If all else fails i will get in a spare switch and do a check.
Can always try updating the firmware of the switch, it may not be handling the server NIC very well. Obviously this would require a reboot and could cause downtime.
A cisco switch by any chance? 2950 or the like?
Can always try updating the firmware of the switch, it may not be handling the server NIC very well. Obviously this would require a reboot and could cause downtime.
A cisco switch by any chance? 2950 or the like?
Did that yesterday as the newer firmware fixed some issues with traffic being blocked between 100T & 1000T ports. Still did not sort the problem out.
Nop its a 3Com 4228G, when they were bought about 2years ago budget did not streach to a Cisco with a couple of Gig ports.
My co is a cheep skate co and there is always limited to no funds for things, its surprising how stuff still works. Some offices still have computers from 99 and servers from the same time that are working away without many problems. Usaly things only get replaced if they have broken or if 1 of the directors just wants to spend money.
Terence
28-04-06, 10:08 AM
As a process of elimination you might want to take a laptop (if you can get one) and try the following...
- test throughput between laptop and client (as you've said this should be ok)
- test throughput with laptop patched directly into switch closest to server (may require crossover cable)
- test throughput with laptop plugged directly into server nic (will require crossover)
Observations from the above may not solve the problem, but should narrow down the problem area.
HTH
Terence
timwilky
28-04-06, 10:08 AM
I have had real problems with 3com switches in the past, particularly with trunking between switches in VLans etc. In the end we ripped out 6 month old kit an replaced it with Cisco
rictus01
28-04-06, 10:15 AM
I'll have to make some assumptions here, sever and clients are on the same switch?
it's not a toy town one?
you're only having problems with the server - switch connection speed?
(which translates to to sever connection to any client)
Ok do you currently have auto negotiate on both ends of the server switch connection? as auto negotiate isn't away compatible between different manufacturers (have you got a sniffer? check the handshake duration), fix one end and leave the other on auto, if that doesn't work try fixing both ends, next would be to add an additional nic to the server and connect that up, try the same test on that link, it should show if there is a compatability issue, after that you're down to swapping the server nic to another brand or the switch (sometime even dropping a hub in the link can sort it as a temp measure).
it's far less common these days but still some stuff doesn't work right although it's all to the same standard.
Cheers Mark.
I'll have to make some assumptions here, sever and clients are on the same switch?Yes
it's not a toy town one?
3COM Superstack 4228G (not brill)
you're only having problems with the server - switch connection speed?
(which translates to to sever connection to any client)
Yes, client to client at 100/full(auto on both client & switch) seems fine, client to server is slow unless client is set to 100/half(switch port), server all this time is set to 1000/full(switch & server)
Ok do you currently have auto negotiate on both ends of the server switch connection? as auto negotiate isn't away compatible between different manufacturers (have you got a sniffer? check the handshake duration), fix one end and leave the other on auto, if that doesn't work try fixing both ends, next would be to add an additional nic to the server and connect that up, try the same test on that link, it should show if there is a compatability issue, after that you're down to swapping the server nic to another brand or the switch (sometime even dropping a hub in the link can sort it as a temp measure).
The server-switch port is set manualy on both ends to 1000/full.
All client-switch ports are set manualy to 100/half at the moment as it was the only way to get better throughput. If the server is forced to 100/full then the client NIC will only auto neg with the switch at 100/half, if i force the client to 100/full it makes no diffrence to speed, its still bad. The only config that works for good thoughput to the server is clients set to 100/half. I have no sniffer tools.
rictus01
28-04-06, 11:01 AM
The server-switch port is set manualy on both ends to 1000/full.
have you tested this from the switch or server end ?
All client-switch ports are set manualy to 100/half at the moment as it was the only way to get better throughput.
but they will work 100/full client to client yes ?
If the server is forced to 100/full then the client NIC will only auto neg with the switch at 100/half, if i force the client to 100/full it makes no diffrence to speed, its still bad . The only config that works for good thoughput to the server is clients set to 100/half you mean client to switch to server. I have no sniffer tools.
Doesn't the 4228G have the two 10/100/1000 rj45 ports and two gbic ports on it, you'll have to remind me as we junked ours a time back.
is the 1000 mb link copper or fibre?
Have you tried changing the port for the server?
or indeed getting it through a gig copper to gbic converter?
does it use any media converters in circuit already?
what cables are you using (cat5, cat5e, cat 6?)
sounds like either the switch has a problem with 1000 to 100 full internal negotiation?
or the gig link isn't working correctly so the switch is having a hard time through putting from that side of the circuit.
has this always been an issue or did it start after any changes to the system?
Cheers Mark.
The server-switch port is set manualy on both ends to 1000/full.
have you tested this from the switch or server end ?
If you mean have i confirmed that they are set correctly, then i have checked both the server and swith. I dont have any other 1000T devices to check throughput.
All client-switch ports are set manualy to 100/half at the moment as it was the only way to get better throughput.
but they will work 100/full client to client yes ?
Yes
If the server is forced to 100/full then the client NIC will only auto neg with the switch at 100/half, if i force the client to 100/full it makes no diffrence to speed, its still bad . The only config that works for good thoughput to the server is clients set to 100/half you mean client to switch to server. I have no sniffer tools.
Yes, Client to Switch 100/half to Server 1000/full, thoughput is good
Doesn't the 4228G have the two 10/100/1000 rj45 ports and two gbic ports on it, you'll have to remind me as we junked ours a time back.
Yes
is the 1000 mb link copper or fibre?
Copper, no fiber used in company
Have you tried changing the port for the server?
Not recently, but possably in the past i will do it again
or indeed getting it through a gig copper to gbic converter?
Ive got no gibc convertors and if i was to get one it would not be worth it and i would just buy a cisco switch
does it use any media converters in circuit already?
No copper to fiber convertors, but some computers use cable splitters, but some comps that dont use have them still have problems anyway
what cables are you using (cat5, cat5e, cat 6?)
I have a fealing that the cab still had Cat5 patch cables, but all the cabling is cat5e.
sounds like either the switch has a problem with 1000 to 100 full internal negotiation?
or the gig link isn't working correctly so the switch is having a hard time through putting from that side of the circuit.
has this always been an issue or did it start after any changes to the system?
The issue has existed ever since the new server went in, but the old server was old and only had 100T connection so no easy comparison.
Cheers Mark.
I will go away and try to nail this on the head, if i realy get peed off i will just dump the switch and get a cisco, which is what i wanted in the first place years ago.
Its not a major killer to them working just its becoming more of an issue now. For various reasons i have never spent lots of time on that offices systems.
vBulletin® , Copyright ©2000-2025, Jelsoft Enterprises Ltd.