HP VPN Firewall Appliances Network Management Configuration Guide

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Table 13 Configuration items
Item Descri
p
tion
Enable STP Globally
Specify whether to enable STP globally:
• Enable—Enables STP globally.
• Disable—Disables STP globally.
Other MSTP configurations can take effect only after you enable STP
globally.
BPDU Protection
Specify whether to enable BPDU guard globally:
• Enable—Enables BPDU guard globally.
• Disable—Disables BPDU guard globally.
BPDU guard can protect the device from malicious BPDU attacks,
making the network topology stable.
Mode
Configure STP to operate in STP mode, RSTP mode, or MSTP mode:
• STP mode—All ports of the device send out STP BPDUs.
• RSTP mode—All ports of the device send out RSTP BPDUs. If the
device detects that it is connected to a legacy STP device, the port
connecting to the legacy STP device automatically migrates to
STP-compatible mode.
• MSTP—All ports of the device send out MSTP BPDUs. If the device
detects that it is connected to a legacy STP device, the port
connecting to the legacy STP device automatically migrates to
STP-compatible mode.
Max Hops
Set the maximum number of hops in an MST region to restrict the region
size.
The setting can take effect only when it is configured on the regional
root bridge.
Path Cost Standard
Specify the standard for path cost calculation. It can be Legacy, IEEE
802.1D-1998, or IEEE 802.1T.
Bridge Diameter
Specify the bridge diameter. Any two stations in a switched network
are interconnected through a specific path composed of a series of
devices. The bridge diameter (or the network diameter) is the number of
devices on the path composed of the most devices.
When you configure the bridge diameter, follow these guidelines:
• The network diameter applies to only the CIST, and not to MSTIs. It
takes effect only after you configure it on the root bridge. Each MST
region is regarded as a device.
• After you set the network diameter, you cannot set the timers.
Instead, the device calculates the forward delay, hello time, and
max age automatically.
Timer Forward Delay
Set the delay for the root and designated ports to transit to the
forwarding state.
The length of the forward delay time is related to the network diameter
of the switched network. The larger the network diameter is, the longer
the forward delay time should be. If the forward delay setting is too
small, temporary redundant paths might be introduced. If the forward
delay setting is too big, it might take a long time for the network to
converge. HP recommends that you use the default setting.