ESRP Master Election

The system determines the ESRP master switch (providing Layer 3 routing and/or Layer 2 switching services for a VLAN) using the following default factors:

• Stickiness—The switch with the higher sticky value has higher priority. When an ESRP domain claims master, its sticky value is set to 1 (available only in extended mode).
• Active ports—The switch that has the greatest number of active ports takes highest precedence.
• Tracking information—Various types of tracking are used to determine if the switch performing the master ESRP function has connectivity to the outside world. ExtremeXOS software supports the following types of tracking:
  • VLAN—Tracks any active port connectivity to one designated VLAN. An ESRP domain can track one VLAN, and the tracked VLAN should not be a member of any other ESRP domain in the system.
  • IP unicast route table entry—Tracks specific learned routes from the IP route table.
  • Ping—Tracks ICMP ping connectivity to specified devices.
  • Environment (health checks)—Tracks the environment of the switch, including power supplies.
  If any of the configured tracking mechanisms fail, the master ESRP switch relinquishes status as master, and remains in slave mode for as long as the tracking mechanism continues to fail.
• ESRP priority—This is a user-defined field. The range of the priority value is 0 to 255; a higher number has higher priority, except for 255. The default priority setting is 0. A priority setting of 255 makes an ESRP switch a standby switch that remains in slave mode until you change the priority setting. We recommend this setting for system maintenance. A switch with a priority setting of 255 will never become the master.
• System MAC address—The switch with the higher MAC address has higher priority.
• Active port weight—The switch that has the highest port weight takes precedence. The bandwidth of the port automatically determines the port weight (available only in extended mode).

You can configure the precedence order of the factors used by the system to determine the master ESRP switch. For more information about configuring the ESRP election metrics, see ESRP Election Algorithms.