If you choose to select a specific mode of operation (rather than auto-negotiation), you should be sure that the link partner supports the same mode. Otherwise, no link will be achieved.
If you select a Full Duplex mode and the link partner supports the same wire speed but not Full Duplex, a link will be achieved, but it will be unstable and will behave erratically.
If you select Auto-Negotiation, the local node will try to match the mode of the link partner, even if the link partner is not set to auto-negotiate, and even if the local node must use a mode which is it is not currently advertising.
Note that if Auto Negotiation is the selected mode, the Current Operational Mode field will indicate which mode was selected by the link partners.
See Setting the Desired Operational Mode, page 2-35, for more information.
Advertised Abilities
For 100Base-TX ports which have been configured to operate in Auto Negotiation mode, this field allows you to select which of the operational modes available to the port can be selected by the negotiating link partners. During Auto Negotiation, each of the link partners will advertise all selected modes in descending bandwidth order: 100Base-TX Full Duplex, 100Base-TX, 10Base-T Full Duplex, and 10Base-T. Of the selected abilities, the highest mode mutually available will automatically be used. If there is no mode mutually advertised, no link will be achieved.
If you have selected a specific operational mode for your 100Base-TX port, the Advertised Abilities do not apply; the selected Advertised Abilities also do not restrict the local node’s ability to set up a link with a partner who is not currently Auto-Negotiating.
