HP VPN Firewall Appliances Network Management Configuration Guide

75
Item Descri
p
tion
Hello Time
Set the Hello time. The Hello time is the interval at which the device
sends hello packets to the surrounding devices to make sure the paths
are fault-free.
An appropriate hello time setting enables the device to timely detect
link failures on the network without using excessive network resources.
If the hello time is set too long, the device takes packet loss as a link
failure and triggers a new spanning tree calculation process. If the
hello time is set too short, the device sends repeated configuration
BPDUs frequently, which adds to the device burden and causes waste
of network resources. HP recommends that you use the default setting.
Max Age
Set the max age. The max age determines how long a configuration
BPDU can be held by the device.
If the max age time setting is too small, the network devices frequently
launches spanning tree calculations and might take network congestion
as a link failure. If the max age setting is too large, the network might
fail to timely detect link failures and fail to timely launch spanning tree
calculations, reducing the auto-sensing capability of the network. HP
recommends that you use the default setting.
Instance
Instance ID Specify the ID of the MSTI to be configured.
Root Type
Specify the role of the device in the MSTI:
• Not Set—The device role is not configured.
• Primary—Configure the device as the root bridge.
• Secondary—Configure the device as a secondary root bridge.
Bridge Priority
Set the bridge priority. The bridge priority of a device is one of the
factors determining whether the device can be elected as the root
bridge.
After specifying the current device as the primary root bridge or a
secondary root bridge, you cannot change the bridge priority of the
device.
TC Protection
Specify whether to enable the TC guard function, that is, protection
against topology change (TC) BPDUs.
When receiving TC BPDUs (the BPDUs used to notify topology
changes), the device flushes its forwarding address entries. If someone
forges TC-BPDUs to attack the device, the device receives a larger
number of TC-BPDUs within a short time and be busy with forwarding
address entry flushing. This affects network stability. With TC guard
enabled, you can prevent frequent flushing of forwarding address
entries.
HP recommends that you keep this function enabled.
TC Protection Threshold
Set the maximum number of forwarding address entry flushes that the
device can perform within a specific time period after it receives the
first TC-BPDU.
Configuring MSTP on a port
1. From the navigation tree, select Network > MSTP > Port.
The page displaying the MSTP information of ports as shown in Figure 48 appears.