81 Chapter3
X-Ring
X-Ring provides a faster redundant recovery than Spanning Tree topology. The action is similar to STP or
RSTP, but the algorithms between them are not the same.
In the X-Ring topology, every switch should be enabled with X-Ring function and two ports should be
assigned as the member ports in the ring. Only one switch in the X-Ring group would be set as the
master switch that one of its two member ports would be blocked, called backup port, and another port is
called working port. Other switches in the X-Ring group are called working switches and their two
member ports are called working ports. When the failure of network connection occurs, the backup port of
the master switch (Ring Master) will automatically become a working port to recover from the failure.
The switch supports the function and interface for setting the switch as the ring master or not. The ring
master can negotiate and place command to other switches in the X-Ring group. If there are 2 or more
switches in master mode, the software will select the switch with lowest MAC address number as the ring
master. The X-Ring master ring mode can be enabled by setting the X-Ring configuration interface. Also,
the user can identify whether the switch is the ring master by checking the R.M. LED indicator on the
panel of the switch.
The system also supports the Couple Ring that can connect 2 or more X-Ring group for the redundant
backup function; Dual Homing function that can prevent connection lose between X-Ring group and
upper level/core switch. Apart from the advantages, Central Ring can handle up to 4 rings in the system
and has the ability to recover from failure within 10 milliseconds.
• Enable Ring: To enable the X-Ring function, tick the checkbox beside the Enable Ring string label. If
this checkbox is not ticked, all the ring functions are unavailable.
¾ Enable Ring Master: Tick the checkbox to enable this switch to be the ring master.
¾ 1st & 2nd Ring Ports: Pull down the selection menu to assign the ports as the member ports.
1st Ring Port is the working port and 2nd Ring Port is the backup port. When 1st Ring Port fails,
the system will automatically upgrade the 2nd Ring Port to be the working port.
• Enable Couple Ring: To enable the coupe ring function, tick the checkbox beside the Enable Couple
Ring string label.
¾ Couple port: Assign the member port which is connected to the other ring group.
¾ Control port: When the Enable Couple Ring checkbox is ticked, you have to assign the
control port to form a couple-ring group between the two X-rings.
• Enable Dual Homing: Set up one of the ports on the switch to be the Dual Homing port. For a switch,
there is only one Dual Homing port. Dual Homing function only works when the X-Ring function
enabled.
• Enable Dual Ring: When this check box is ticked, the ‘Enable Ring Master’ check box will then also
be enabled by the system which means this equipment is assigned as the Ring Master. The Dual Ring
differs from the Couple Ring in that it only needs a unit to form a redundant linking system of two rings.
• And then, click Apply to apply the configuration.