Enabling Loop Guard; Enabling Tc-Bpdu Guard - HP 6600 Configuration Manual

Step
2. Enter interface view or port
group view.
3. Enable the root guard
function for the ports.

Enabling loop guard

By continuing to receive BPDUs from the upstream device, a device can maintain the state of the root port
and blocked ports. However, link congestion or unidirectional link failures might cause these ports to fail
to receive BPDUs from upstream devices. The device will reselect the port roles: Those ports in forwarding
state that failed to receive upstream BPDUs will become designated ports, and the blocked ports will
transit to the forwarding state, resulting in loops in the switched network. The loop guard function can
suppress the occurrence of such loops.
The initial state of a loop guard-enabled port is discarding in every MSTI. When the port receives BPDUs,
it transits its state. Otherwise, it stays in the discarding state to prevent temporary loops.
Configuration restrictions and guidelines
Configure loop guard on the root port and alternate ports of a device.
•
Do not enable loop guard on a port that connects user terminals. Otherwise, the port will stay in the
•
discarding state in all MSTIs because it cannot receive BPDUs.
• You cannot configure edge port settings and loop guard, or configure root guard and loop guard
on a port at the same time.
Configuration procedure
To enable loop guard:
Step
1. Enter system view.
2. Enter interface view or port
group view.
3. Enable the loop guard
function for the ports.

Enabling TC-BPDU guard

When a device receives topology change (TC) BPDUs (the BPDUs that notify devices of topology
changes), the device flushes the forwarding address entries. If someone forges TC-BPDUs to attack the
device, the device will receive a large number of TC-BPDUs within a short time and be busy with flushing
forwarding address entries. This affects network stability.
Command
•
Enter Ethernet interface view or Layer 2
aggregate interface view:
interface interface-type interface-number
•
Enter port group view:
port-group manual port-group-name
stp root-protection
Command
system-view
•
Enter Ethernet interface view or Layer 2
aggregate interface view:
interface interface-type interface-number
•
Enter port group view:
port-group manual port-group-name
stp loop-protection
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Remarks
Use one of the commands.
By default, root guard is
disabled.
Remarks
N/A
Use one of the commands.
By default, loop guard is
disabled.