Alcatel Unleashed

Hi

Some time ago our network switches were upgraded to Alcatel 6850-24L units. Until then we had some copper links to media convertors (and then on to Cisco L3 switches). Both the switches and media convertors were set to 100/full duplex manually and the network was successful.

After upgrading to the 6850 units it was discovered that setting manual 100/full duplex on the Alacatel switch resulted in 'link down'. I have since found that the only two options are to:

1. Enable auto-negotiation on both 6850 and FOC (Note: switch reports link operating at 100/full duplex)
2. Use 100/half duplex manual settings. (obviously don't want to do this)

Whilst I will probably now use auto-negotiation, I am keen to understand why selecting manual full duplex on the switch does not work and would be most grateful for an explanation or any clues as to why this is.

Many Thanks

Some NICs can fall to half-duplex, even though both sites the switch and NIC are manually configured for 100full. This is because auto-negotiation link detection still operates. Also be sure to disable auto-negotiation on the Alcatel site. This can be helpful

Issue turned out to be that we had not disabled auto-negotiation properly using the WebView GUI, just set manual speed and duplex settings. Found the problem quickly using CLI.

Thanks