Stp Root-Protection; Stp Tc-Protection - 3Com 8807 Command Reference Manual

MSTP Configuration Commands 203

stp root-protection

Syntax
stp root-protection
undo stp root-protection
View
Ethernet port view
Parameter
None
Description
Use the stp root-protection command to enable on Root protection the switch.
Use the undo stp root-protection command to restore the default state of Root
protection.
By default, Root protection is disabled.
In case of configuration error or malicious attack, the legal primary root may
receive the BPDU with a higher priority and then loose its place, which causes
network topology change errors. Due to the illegal change, the traffic supposed to
travel over the high-speed link may be pulled to the low-speed link and congestion
will occur on the network.
MSTP provides Root protection function to protect the root bridge: The port
configured with Root protection only plays a role of designated port on every
instance. Whenever such a port receives a higher-priority BPDU, it will be set to
listening state and not forward packets any more (as if the link to the port is
disconnected). If the port has not received any higher-priority BPDU for a certain
period of time thereafter, it will resume the normal state.
Related command: stp interface root-protection.
Example
# Enable Root protection on the Ethernet2/1/1 port of the switch.
<SW8800>system-view
System View: return to User View with Ctrl+Z.
[SW8800] interface Ethernet2/1/1
[3Com-Ethernet2/1/1] stp root-protection

stp tc-protection

Syntax
stp tc-protection enable
stp tc-protection disable
View
System view
Parameter
None