R3721-F3210-F3171-HP High-End Firewalls Network Management Configuration Guide-6PW101

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Spanning tree implementations vary with vendors, and the configuration digests calculated using private
keys is different, so devices of different vendors in the same MST region cannot communicate with each
other.
To enable communication between an HP device and a third-party device, enable the Digest Snooping
feature on the port connecting the HP device to the third-party device in the same MST region.
NOTE:
Before enabling Digest Snooping, make sure that associated devices of different vendors are connected
and run spanning tree protocols.
Configuration procedure
You can enable Digest Snooping only on the HP device that is connected to a third-party device that uses
its private key to calculate the configuration digest.
To configure Digest Snooping:
Ste
p
Command Remarks
1. Enter system view.
system-view N/A
2. Enter Ethernet interface view or
Layer 2 aggregate interface view.
interface interface-type
interface-number
N/A
3. Enable Digest Snooping on the
interface.
stp config-digest-snooping Disabled by default.
4. Return to system view.
quit N/A
5. Enable global Digest Snooping.
stp config-digest-snooping
Disabled by default.
CAUTION:
• With the Digest Snooping feature enabled, comparison of configuration digest is not needed for
in-the-same-region check, so the VLAN-to-instance mappings must be the same on associated ports.
• With global Digest Snooping enabled, modification of VLAN-to-instance mappings and removing of
the current region configuration using the undo stp region-configuration command are not allowed.
You can only modify the region name and revision level.
• To make Digest Snooping take effect, you must enable it both globally and on associated ports. To make
the configuration effective on all configured ports and while reducing impact on the network, enable
Digest Snooping on all associated ports first and then globally.
• To prevent loops, do not enable Digest Snooping on MST region edge ports.
• HP recommends you to enable Digest Snooping first and then the spanning tree feature. To avoid traffic
interruption, do not configure Digest Snooping when the network is already working well.
Digest Snooping configuration example
1. Network requirements
As shown in Figure 53, Device A and Device B connect to Device
C, which is a third-party device.
All these devices are in the same region.
Enable Digest Snooping on Device A’s and Device B’s ports that connect to Device C, so that the
three devices can communicate with one another.