The interface speed of a link can be determined on the interface details web page for the interface.

The speed and duplex setting is available for viewing in the Interface Summary section.

The interface speed displays the speed that the device reports for the interface in the SNMP ifSpeed OID, or ifHighSpeed if the ifSpeed is invalid.

Interface duplex is queried from the device via dot3StatsDuplexStatus (RFC 2665). If this OID is not available, it will estimate (with a red *) the duplex setting based on the presence or absence of collisions on the interface.