New Stack Member Joining and Stack Merging
Joining of a Stack Member
A new member switch can join a running single-chassis stack (a standalone switch running the stacking function). In Figure 1-13, SwitchA is a single-chassis stack. After SwitchB joins the stack, the two switches set up a new stack. Then SwitchA becomes the master switch, and SwitchB becomes the standby switch.
- After two switches are connected using stack cables, one switch is configured with the stacking function and restarted. This switch enters the single-chassis stack state. After the other switch is configured with the stacking function and restarted, it joins the stack as the standby switch.
- In a running two-chassis stack, one switch restarts and rejoins the stack as the standby switch.
Stack Merging
Two stacks in the running state can merge into one stack. In Figure 1-14, two single-chassis stacks merge into one and elect a master switch (following the same master election rules used in a stack). The master switch retains its original configuration, and its services are not affected. The standby switch restarts, joins the new stack as the standby switch, and synchronizes the configuration file with the master switch. Original services on this switch are interrupted.
- After two switches are configured with the stacking function and restarted, they run as single-chassis stacks. After they are connected using stack cables, they merge into one stack.
- A stack splits due to a failure of a stack link or member switch. When the link or switch recovers, the two single-chassis stacks merge into one.