Hi,
Switch# show switch
It will list all switches in the stack with number and MAC addresses. Through MAC address, you can refer it physically to the switch (rear) you want to become master of the stack. Now check that switch number from the "show switch" output.
Switch# config t
Switch(config)# switch switch_number(1-9) priority 15
Priority 15 makes the switch master of the stack. You may want to identify the backup by setting the priority to 14.
Take note that if you enable L3 Routing and create VLAN interfaces. The VLAN interfaces MAC Address is pooled from current master switch. If the master switch is replaced, the MAC Address will change for all VLAN interfaces, you have to remember this specially if you have firewall (notably old PIX, old NOKIA/Checkpoint) or servers (notably UNIX and Windows NT4) will not automatically learn the new MAC address. You need to login to those devices and clear arp cache, if not you have to wait 4 hours.
Regards,
Dandy
