100 Mhz full duplex => +++ collisions

Hi,

I small question about my lan and the half and full duplex modes.

I have a lan with 4 computers, 3 (desktop) on 98SE and one (laptop) on XP Home. 3 D-LINK DFE-530 TX PCI Fast Ethernet cards and 1 (laptop) Realtec RTL8139 PCI (I suppose the chip is on the motherboard) and a Fast hub (no brand) and CAT 5 cables.

The lan uses TCP/IP for file, printer and internet sharing. One of the 98SEs (PIII 800Mhz) serves as a non dedicated server for the files, printer and the ADSL internet connection. Zone Alert Pro on all computers. Norton AV on the server and the laptop.

Here is the question: if I set the connection mode to "Auto" on all cards, the connection established will be 100Mhz HALF duplex. If I force the setting to 100MHz FULL duplex, the collision light on the hub light is almost constantly on. In HALF duplex, I have rare collisions.

Any ideas and/or help will be appreciated

Regards.

Robby

 

If you have any way to tell what the actual collision rate is, that would be interesting.

Your network as you descirbe it and assuming that all parts (nics, hub, cables) are in good shape shouldn't load a 100mbs network enough to be noticed. Full duplex should generate a few more but still not a significant amount.

Also check the cards (ipconfig /all or winipcfg /all) and see what node type. M-node (Hybrid) will generate the least superfluous traffic while B-node (broadcast) will generate the most. But even so, there just isn't enough equipment running to cause problems unless something is busted.

Maybe one of the nics starts broadcast storming in full duplex mode. Be worth setting them to full one at a time and see if a single machine causes the problem.

 

Thnx for your message. I'm not in the office today so I'll only be able to test tomorrow.

Do you know of any utilities that can calculate the collision rate ? I have "IP Tools" and I see no errors on the TCP/IP but no collision meter.

How will the lan work if some cards are on half and others are on full duplex ???

Regards

 

Some free packet sniffing utilities Here.

As long as the wiring can support it and the hub/switch port and NIC agree on speed and duplexing, no problems. 10Mb half or full, 100Mb half or full, Gb, all will play nicely together.

If a NIC running 10Mb half duplex talks to a NIC running 100Mb full duplex, they do so at 10Mb half duplex.

Note to any reading this who are hazy on half vs. full duplex:
Half duplex = I talk and then I listen and then I talk.
Full duplex = I talk and listen at the same time.

 

Hi,

I forced one then 2 comp. to 100MHz full duplex and initiated a search for *.* over the lan. The collision blinked but not too much.

Things get MUCH worst when I use NERO for my backups. Nero runs on the non dedicated server (PIII 800 on 98 SE) and reads files from the 2 other 98SE and this makes the collision led blink almost as fast as the transmit leds and the file reading (into cache) slows down in Nero.

When I run winipcfg /all, I get "Type of node: "To diffuse "! I suppose that this is a bad translation (my Win is French) for Broadcast. Ipconfig /all doesnt state the type of node ?!?!

I have D/Led and installed Ethereal but I don'y know what to look for as there are too many informations.

Regards

Robby

 

M$ article on node types, how each operates, and how to change to the one you want is Here.