Configuring The Switch To Support Standard Or Legacy Mstp Packet Format; Configuring Digest Snooping - H3C S9500 Series Operation Manual

Operation Manual – MSTP
H3C S9500 Series Routing Switches
1.2.21 Configuring the Switch to Support Standard or Legacy MSTP Packet
Format
Currently, S9500 series routing switches support legacy and standard MSTP packet
format.
When a switch connects to H3C devices, the switch will adopt the legacy STP packet
format. When connecting to devices supporting standard STP, the switch will adopt
standard STP packet format.
In addition, ports of the switch are self-adaptive. That is, the switch can automatically
adjust the outbound packet format according to the inbound packet format.
Table 1-34 Enable a port to send and process MSTP packets in specified format
Enter system view
Enter Ethernet port view
Configure the current port to
send and process MSTP
packets in specified format

1.2.22 Configuring Digest Snooping

I. Introduction to digest snooping
According to IEEE 802.1s, two interconnected switches can communicate with each
other through multiple spanning tree instances (MSTIs) in a multiple spanning tree
protocol (MSTP) region only when they are configured with the same region settings.
With MSTP, interconnected switches determine whether or not they are in the same
region by checking the configuration IDs of the bridge protocol data units (BPDUs)
between them. (A configuration ID comprises information such as region ID,
configuration digest.)
As switches of some manufacturers come with some private protocols concerning
spanning trees, a switch of this type cannot communicate with other switches in an
MSTP region even if it is configured with the same MSTP region settings as other
switches in the MSTP region.
Digest snooping addresses this interoperability problem. Digest snooping enables a
switch to track and maintain configuration digests of other switches that are in the same
region and come from other manufacturers by examining their BPDUs. It also enables
the switch to insert corresponding configuration digests in its BPDUs destined for these
switches. In this way, switches of different manufacturers are capable of
communicating with each other in an MSTP region.
To do... Use the command...
system-view
interface interface-type
interface-number
stp compliance { legacy |
dot1s | auto }
1-36
Chapter 1 MSTP Configuration
Remarks
—
—
By default, a port
operates in auto
mode.