To ensure reliability, configure the relay mode on a maximum of four Eth-Trunks in a stack.
Each Eth-Trunk can have a maximum eight member interfaces. Therefore, when a stack
contains nine member switches, one Eth-Trunk cannot provide detection links for all the
member switches. In this case, multiple Eth-Trunks need to be configured to ensure that a
detection link is available between any two member switches. As shown in Figure 2-20,
Eth-Trunk1 provides detection links for Switch1 to Switch8, Eth-Trunk2 provides detection
links for Switch2 to Switch9, and Eth-Trunk3 provides detection links for Switch1 and
Switch9.
Figure 2-20 MAD relay detection on multiple Eth-Trunks
2.9.2 MAD Collision Handling
After a stack splits, the MAD split detection mechanism detects multiple stacks in Active state
(indicating that the stacks are working normally). Then the MAD collision handling
mechanism retains the stack with the original master switch in Active state and turns the other
stacks into Recovery state (stacks do not work in this state). Member switches in the stacks in
Recovery state shut down all their physical ports (generally service ports) except reserved
ports, so that these stacks do not forward service packets. By default, only physical member
ports of stack ports are reserved ports. You can run a command to specify other ports, such as
the port used for remote login, as reserved ports.
2.9.3 MAD Fault Recovery
After a fault link recovers, the MAD fault recovery mechanism merges the stacks into one.
Stacks can merge in either of the following ways:
After the fault link recovers, the stacks in Recovery state restart and merge with the stack
in Active state, and restore the shutdown service ports to Up state. Then the entire stack
recovers.
If the stack in Active state is also faulty before the faulty link recovers, remove the stack
in Active state first, and use a command to start the stacks in Recovery state, enabling the
stacks to take over services on the original stack in Active state. After the original stack
in Active state and the faulty link recover, the stacks can merge.
To Next Page
Loading...
Need help?
General