An Ethernet port working in 1000BASE-Tx mode requires a continuous stream of data between both connected partners in order to stay synchronized. The nature of this requires the two ends to have a synchronized clock to transmit data. IEEE 802.3 introduced the concept of a master and a slave for this type of connection. The master provides the clocking for data transmission in both directions while the slave synchronizes to this clock. The roles of clocking master and slave are shared out in the automatic negotiation phase. This aspect can normally be ignored since automatic negotiation works very well in most cases. In some cases it may be necessary to influence master-slave negotiation. For this purpose the following values can be set for clocking:
SNMP ID: 2.23.21.5
Telnet path: /Setup/Interfaces/LAN-Interfaces/Clock-Role
Possible values:
- Slave-Preferred: This is the recommended default setting for devices that are not used as a switch. During the negotiation phase, the port will attempt to negotiate the slave role. It will accept the role of master if necessary.
- Master-Preferred: During the negotiation phase, the port will attempt to negotiate the master role. It will accept the role of slave if necessary.
- Slave: The port is set to the role slave only. A connection will be refused if both connection partners use the role of slave.
- Master: The port is set to the role master only. A connection will be refused if both connection partners use the role of master.