On Thu, 30 Aug 2001 12:18:53 -0400 David Grove <pete@petes-place.com> wrote:
Well, Rick, I'm no network expert, but I have noticed a difference between what people tell me, what the box says, and real life.
I use the LNE100TX and 3Com 3C905B/C cards only. Now, supposedly, when I have a 10Mbps card going to my hub, it's supposed to slow the whole network down to 10Mbps. However, I seem to have an oddball (advanced or something) hub where only the 10Mbps line would run at 10Mbps. (Everyone: No, this is not a switch. This is not a switch. This is not a switch.) Anyway, plugging in a 10Mbps card into a primarily 100Mbps hub is /supposedly/ going to slow everything down.
You will link at 100 if your card is 100, but the traffic is still only 10. Don't confuse what you bind at and the actual data transfer speed. It is not physically possible to have a single network segment (what a hub gives) running at two speeds. It's not a matter of "well, my hub is different". No, it's not.
However (from the verbiage on the side of my new switches (ahem)), it doesn't make any difference because the 100Mbps is shared among the machines that are talking on "most" hubs. Hubs also "are only capable of half duplex" meaning 50Mbps up and 50Mbps down, shared among machines. Now, this I can attest to because I ran into it building my own linux distro (linuxfromscratch.org, not recommended to the impatient or anyone with a sex life), my NIC belched out that the network was running half duplex.
This is not corrent either. Switches or hubs or NICs can run at either full or half duplex, depending on their construction. Lots of 10 & 100 full duplex hubs out there.