Solved: Speed/Duplex Question

lamav · ‎10-23-2008

if its determined that a LAN device is too far away from the switch, and its presently operating at 1000/full, is there any sense in changing the duplex setting from full to half?

If the LAN device (printer) can support it, I can see changing the speed setting to a slower speed (same CAT 6 cable), like 10 Mbps, but why change the duplex setting? How does that help? I think it would make it worse, if anything. Now you run the risk of creating collisions for no reason....I would leave it at 10/full.

Thanks

Istvan_Rabai · ‎10-23-2008

Hi Victor,

Yes, I agree with you that there is no advantage to change it to half duplex.

At least I can't find one.

Cheers:

Istvan

View solution in original post

Istvan_Rabai · ‎10-23-2008

I think I agree with you Victor.

10 Mbps Ethernet should work on a 100m distance over CAT5/6 UTP cable.

Or do you need more distance?

Cheers:

Istvan

lamav · ‎10-23-2008

Istvan:

The speed is not what I was asking about.

my question revolves areound the duplex setting.

I am wondering what the advantage is of changing the duplex setting to half when you have a distance issue. I don tthink ther eis any.

It should be changed to 10 full.Agree?

MUHAMMAD SHAHEEN · ‎10-23-2008

Hi Victor,

There is no point to fix the speed/duplex at one end and leaving the other device at default as this always cause problems. I agree with you, you don't get any benefit if you are doing because of the distance. This option is only to help when different vendor equipments run into problems of correctly negotiating speed/duplex.

In many cases it is better to leave at auto/auto and only fix this if there is a prformance problem or you are seeing errors on the interface.

Hope This Helps....

Shaheen

Istvan_Rabai · ‎10-23-2008

Hi Victor,

Yes, I agree with you that there is no advantage to change it to half duplex.

At least I can't find one.

Cheers:

Istvan

Joseph W. Doherty · ‎10-23-2008

Victor, as far as I know for copper Ethernet, duplex setting nor speed should have anything to do with distance. Lower speed would allow lower grade CAT, but again, don't believe has impact on distance.

PS:

Reason for above, I believe has more to do with certain Ethernet timings and signal reflections, not strength of signal being usable by host at end of long copper run.