3Com SuperStack 4 Configuration Manual page 245

e Enable the Root protection function on every designated port.
[SW5500]interface gigabitethernet 2/0/1
[SW5500-GigabitEthernet2/0/1]stp root-protection
[SW5500]interface gigabitethernet 2/0/2
[SW5500-GigabitEthernet2/0/2]stp root-protection
2 Configure Switch B
a Enable RSTP globally.
[SW5500]stp enable
b The port RSTP defaults are enabled after global RSTP is enabled. You can
disable RSTP on those ports that are not involved in RSTP calculation, however,
be careful and do not disable those involved. (The following configuration
takes GigabitEthernet 1/0/4 as an example.)
[SW5500]interface gigabitethernet 1/0/4
[SW5500-GigabitEthernet1/0/4]stp disable
c Configure Switch C and Switch B to serve as standby of each other and sets the
Bridge priority of Switch B to 4096.
[SW5500]stp priority 4096
d Enable the Root protection function on every designated port.
[SW5500]interface gigabitethernet 1/0/1
[SW5500-GigabitEthernet1/0/1]stp root-protection
[SW5500]interface gigabitethernet 1/0/2
[SW5500-GigabitEthernet1/0/2]stp root-protection
[SW5500]interface gigabitethernet 1/0/3
[SW5500-GigabitEthernet1/0/3]stp root-protection
RSTP operating mode, time parameters, and port parameters take default
values.
3 Configure Switch C
a Enable RSTP globally.
[SW5500]stp enable
b The port RSTP defaults are enabled after global RSTP is enabled. You can
disable RSTP on those ports that are not involved in RSTP calculation, however,
be careful and do not disable those involved. (The following configuration
takes GigabitEthernet 1/0/4 as an example.)
[SW5500]interface gigabitethernet 1/0/4
[SW5500-GigabitEthernet1/0/4]stp disable
c Configure Switch C and Switch B to serve as standby of each other and sets the
Bridge priority of Switch C to 8192.
[SW5500]stp priority 8192
d Enable the Root protection function on every designated port.
[SW5500]interface gigabitethernet 1/0/1
[SW5500-GigabitEthernet1/0/1]stp root-protection
[SW5500]interface gigabitethernet 1/0/2
[SW5500-GigabitEthernet1/0/2]stp root-protection
[SW5500]interface gigabitethernet 1/0/3
[SW5500-GigabitEthernet1/0/3]stp root-protection
RSTP Configuration Example 257