HP A3100-8 v2 SI Configuration Manual page 81

Because MSTP implementations vary with vendors, the configuration digests calculated via private keys
are different. The different vendors' devices in the same MST region can not communicate with each
other.
Enabling the Digest Snooping feature on the port that connects the local device to a third-party device in
the same MST region can make the two devices communicate with each other.
NOTE:
Before you enable Digest Snooping, ensure that associated devices of different vendors are connected and
run MSTP.
Configuring the Digest Snooping feature
You can enable Digest Snooping only on a device that is connected to a third-party device that uses its
private key to calculate the configuration digest.
Follow these steps to configure Digest Snooping:
To do...
Enter system view
Enter interface
view or port
group view
Enable Digest Snooping on the interface
or port group
Return to system view
Enable global Digest Snooping
CAUTION:
• With digest snooping enabled, in-the-same-region verification does not require comparison of
configuration digest, 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 removal of the
•
current region configuration via the undo stp region-configuration command are not allowed. You can
modify only the region name and revision level.
To make Digest Snooping take effect, you must enable Digest Snooping both globally and on associated
•
ports. HP recommends that you enable Digest Snooping on all associated ports first and then enable it
globally. This will make the configuration take effect on all configured ports and reduce impact on the
network.
• HP recommends that you enable Digest Snooping first and then MSTP. To avoid causing traffic
interruption, do not configure Digest Snooping when the network is already working well.
Digest Snooping configuration example
Network requirements
1.
Use the command...
system-view
Enter Ethernet
interface view or interface interface-type
Layer 2 aggregate interface-number
interface view
port-group manual
Enter port group view
port-group-name
stp config-digest-snooping
quit
stp config-digest-snooping
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Remarks
—
Required
Use either command.
Required
Disabled by default.
—
Required
Disabled by default.