Enabling Bpdu Guard; Enabling Root Guard - HP 6600 Configuration Manual

Enabling BPDU guard

For access layer devices, access ports can directly connect to user terminals (such as PCs) or file servers.
Access ports are configured as edge ports to allow rapid transition. When these ports receive
configuration BPDUs, the system automatically sets the ports as non-edge ports and starts a new
spanning tree calculation process. This causes a change of network topology. Under normal conditions,
these ports should not receive configuration BPDUs. However, if someone forges configuration BPDUs
maliciously to attack the devices, the network will become unstable.
The spanning tree protocol provides the BPDU guard function to protect the system against such attacks.
With the BPDU guard function enabled on devices, when edge ports receive configuration BPDUs, the
system closes these ports and notifies the NMS that they have been closed by the spanning tree protocol.
The device will reactivate closed ports after the port status detection timer expires. For more information
about the port status detection timer, see Fundamentals Configuration Guide.
Configure BPDU guard on a device with edge ports configured. BPDU guard does not take effect on
loopback testing-enabled ports. For more information about loopback testing, see Interface
Configuration Guide.
To enable BPDU guard:
Step
1. Enter system view.
2. Enable the BPDU guard
function for the device.

Enabling root guard

The root bridge and secondary root bridge of a spanning tree should be located in the same MST region.
Especially for the CIST, the root bridge and secondary root bridge are put in a high-bandwidth core
region during network design. However, because of possible configuration errors or malicious attacks on
the network, the legal root bridge might receive a configuration BPDU with a higher priority. Another
device will supersede the current legal root bridge, causing an undesired change in the network topology.
The traffic that should go over high-speed links is switched to low-speed links, resulting in network
congestion.
To prevent this situation, MSTP provides the root guard function. If the root guard function is enabled on
a port of a root bridge, this port plays the role of designated port on all MSTIs. After this port receives a
configuration BPDU with a higher priority from an MSTI, it immediately sets that port to the listening state
in the MSTI, without forwarding the packet. This is equivalent to disconnecting the link connected with
this port in the MSTI. If the port receives no BPDUs with a higher priority after a period that is twice the
forwarding delay, it reverts to its original state.
Configure root guard on a designated port. You cannot configure root guard and loop guard on a port
at the same time.
To enable root guard:
Step
1. Enter system view.
Command
system-view
stp bpdu-protection
Command
system-view
74
Remarks
N/A
By default, BPDU guard is
disabled.
Remarks
N/A