I am experiencing significant collisions on a 100BaseT network when just one Wintel computer on the lan is recieving packets from a NT Server (4.0). As more computers are switched on more collisions occur. The nic on the server is set to auto the same as the workststion. I have connected the server to the 100baseT hub, workstation on the same hub, when only these two machine are on and communicating - still the same problem. I have set the server nic to 100 half duplex likewise the workstation every other device on the network turned of (bar the active equipment) - still the same problem. The server card is not chattering nor is the card on the workstation. I have swapped hubs (twice), still no resolution. Any help would be appreciate.
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Network Collisions
- Thread starter rewas
- Start date
Salvalinus
MIS
When you say "significant" what do you mean? What percentage (collisions/packets out)? How much data are you sending while the collisions are occurring? Is it possible that you are overloading the 100Mbps half duplex connection? Is this just a single HUB with no other connections but the two computers? How do you know that neither of the PC NICs is chattering? Are any error counters climbing when you see this problem?
- Thread starter
- #3
Thanks for your response<br>
<br>
By significant = appears to be every packet sent, although not measured with a Fluke or similar the orange collision light on the hub and the switch is on all the time with some brief flickering in the following scenario<br>
<br>
Server - full duplex 100Mb with brand name card to same brand switch (10/100 autosensing - full duplex)uplinked via UTP to same brand hub (10/100 half duplex - autosensing)to workstation with same brand card, set to full duplex. I am running an mpg or file transfer (whatever)to the workstation from the server. All other devices removed from the hub and the switch (removing variables). I have tried half duplex or combinations of both (as well as auto). I have plugged the server directly into the switch and the workstation directly into the hub (removing variables - data points) I have changed fly leads (removing variables).<br>
<br>
It works perfectly when the workstation is connected directly into the switch along with the server, both on full duplex, no collisions - as you would expect - if the server is connected straight into the hub along with the work station, collisions (all other devices removed - only for testing). Ahh hub I hear you say - read on.<br>
<br>
The cards in both the server and the workstation have been replaced in case of chattering. Since I submitted this post I have configured another NT box to distribute a similar and same file - collisions within acceptable limits. Other devices are normally connected into the switch and the hub - I have just removed them in an attempt to isolate the problem. Everything seems to point back to the server as the originator of the problem but the NIC has been changed - faulty motherboard, protocol being corrupted???? The only protocol running on the workstation and the server is TCP/IP.<br>
<br>
Next move - install service pack 6a, change switch and hub to another brand - however the name brand we have is good.<br>
Get fluke meter start thorough analysis<br>
<br>
Again thanks for your response - the makers of the switch, hub and cards (same organisation) cannot work it out - I cannot work it out nor can any of the engineers that have looked at the problem.<br>
<br>
This network is state of the art. Every hub or switch has its own fibre pair connected irectly back to a switch - collisions should not be occuring - but --- thats life. <br>
<br>
Any Heeeeelllllllp
<br>
By significant = appears to be every packet sent, although not measured with a Fluke or similar the orange collision light on the hub and the switch is on all the time with some brief flickering in the following scenario<br>
<br>
Server - full duplex 100Mb with brand name card to same brand switch (10/100 autosensing - full duplex)uplinked via UTP to same brand hub (10/100 half duplex - autosensing)to workstation with same brand card, set to full duplex. I am running an mpg or file transfer (whatever)to the workstation from the server. All other devices removed from the hub and the switch (removing variables). I have tried half duplex or combinations of both (as well as auto). I have plugged the server directly into the switch and the workstation directly into the hub (removing variables - data points) I have changed fly leads (removing variables).<br>
<br>
It works perfectly when the workstation is connected directly into the switch along with the server, both on full duplex, no collisions - as you would expect - if the server is connected straight into the hub along with the work station, collisions (all other devices removed - only for testing). Ahh hub I hear you say - read on.<br>
<br>
The cards in both the server and the workstation have been replaced in case of chattering. Since I submitted this post I have configured another NT box to distribute a similar and same file - collisions within acceptable limits. Other devices are normally connected into the switch and the hub - I have just removed them in an attempt to isolate the problem. Everything seems to point back to the server as the originator of the problem but the NIC has been changed - faulty motherboard, protocol being corrupted???? The only protocol running on the workstation and the server is TCP/IP.<br>
<br>
Next move - install service pack 6a, change switch and hub to another brand - however the name brand we have is good.<br>
Get fluke meter start thorough analysis<br>
<br>
Again thanks for your response - the makers of the switch, hub and cards (same organisation) cannot work it out - I cannot work it out nor can any of the engineers that have looked at the problem.<br>
<br>
This network is state of the art. Every hub or switch has its own fibre pair connected irectly back to a switch - collisions should not be occuring - but --- thats life. <br>
<br>
Any Heeeeelllllllp
Salvalinus
MIS
How long is that fiber segment? I believe the max distance for 100baseFX Half-duplex to a repeater/HUB is only something like 160m. I have had trouble with long fiber distances even switch to switch that were auto-negotiated to half-duplex. Since you are using a hub on one side you will, of course, have to use half-duplex. Provided the distances are good, have you tested the fiber to make sure you don't have too much attenuation or loss?<br>
<br>
Can you confirm that the NIC on the server is actually getting set to half-duplex? I seem to remember some combination of NIC and driver that even though you set it to half-duplex in NT the thing wouldn't actually come up that way, or was that full-duplex, at any rate things seem to point to the specific combination of hardware and software on that NT server.<br>
<br>
Good luck with this one, sounds like one of those problems that we all dread.
<br>
Can you confirm that the NIC on the server is actually getting set to half-duplex? I seem to remember some combination of NIC and driver that even though you set it to half-duplex in NT the thing wouldn't actually come up that way, or was that full-duplex, at any rate things seem to point to the specific combination of hardware and software on that NT server.<br>
<br>
Good luck with this one, sounds like one of those problems that we all dread.
- Thread starter
- #5
what is the brand/model is your switch,how are the fibre ports configured,is there a<br>
remote monitoring software for this system?kind of sounds like you have some <br>
components that are at the other end of the I.E.E.E spec than some others,what is<br>
linking the hubs to your fibre,transceivers in the hub or third party gear,try using only<br>
CAT5 as a test,it will remove 50% of possible causes...
remote monitoring software for this system?kind of sounds like you have some <br>
components that are at the other end of the I.E.E.E spec than some others,what is<br>
linking the hubs to your fibre,transceivers in the hub or third party gear,try using only<br>
CAT5 as a test,it will remove 50% of possible causes...
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