Command Manual - STP
Quidway S6500 Series Ethernet Switches
Chapter 3 Digest Snooping Configuration
Commands
Huawei Technologies Proprietary
3-1
Chapter 3 Digest Snooping Configuration
Commands
3.1 Digest Snooping Configuration Commands
3.1.1 stp config-digest-snooping
Syntax
stp config
-
digest
-
snooping
undo stp config
-
digest
-
snooping
View
System view, Ethernet interface view
Parameter
None
Description
Using the
stp config
-
digest
-
snooping
command, you can enable digest snooping.
Using the
undo stp config
-
digest
-
snooping
command, you can disable digest
snooping.
Digest snooping is disabled by default.
According to IEEE 802.1s, two connected switches can communicate through MSTIs
(multiple spanning tree instances) in a MSTP (multiple spanning tree protocol) domain
only when they are configured with the same domain settings. With MSTP employed,
interconnected switches determine whether or not they are in the same domain by
checking the configuration IDs of the BPDUs between them. (Configuration ID
comprises information such as domain ID and configuration digest.)
As some switches come with some proprietary protocols concerning STP employed,
they cannot communicate with other switches in MSTP domains even both of them are
configured with the same domain configuration settings.
This can be overcome by implementing digest snooping. Digest snooping enables a
switch to track and maintain configuration digests of other switches that are in the same
domain by examining their BPDUs and insert corresponding configuration digests in its
BPDUs destined for these switches, through which switches of different type are
capable of communicating with each other in a MSTP domain.