LAN Speed and Duplex Setting

[sumitv]

Hi,

Using ethtool I can set LAN speed and duplex setting.
I have Windows PC1 configured at 100MBPS Full Duplex. I have a linux PC configured in auto-negotiation. Windows PC1 can ping linux PC2 using cross over ethernet cable but not using straight cable.

Also if I set linux PC2 in 100MBPS Full Duplex mode and Windows PC1 in 100MBPS Full Duplex mode ping is not successful eiether using straight or cross over cable.

Is the second PC need to be in auto negotiation mode?
Please clear if I am making any mistake fundamentally.

Regards,
Sumit

[Rubberman]

I'd check the settings on your switch/bridge/router. I had similar problems in the past when the switch was set to half-duplex and the computer was running full-duplex. I don't know about Windows, but it may well auto-negotiate even if it is set to full-duplex mode.

[sumitv]

Thanks for the information. But I am connecting two PCs directly through ethernet cable without using switch/bridge/router.

If I configure both the cards of PC on same speed, should they be able to communicate?

Regards,
Sumit

[Rubberman]

Well, you indicated that you were able to communicate when Windows was in full-duplex mode, and Linux was in auto-negotiate mode with a cross-over cable. This means that neither system has the ability to detect whether or not it needs to switch tx/rcv lines. A lot of systems these days don't care if the cable is straight, or a patch (cross-over) cable. So, use the cross-over cable. As to why it won't communicate when they are both in full-duplex mode I cannot say, so go with what works.