3Com Switch 4500 Family Manual page 244

[Sysname] stp interface Ethernet 1/0/1 transmit-limit 15
# Set the maximum number of configuration BPDUs that can be transmitted through Ethernet 1/0/2,
Ethernet 1/0/3 and Ethernet 1/0/4 in each hello time to 15 in system view.
<Sysname> system-view
System View: return to User View with Ctrl+Z.
[Sysname] stp interface Ethernet 1/0/2 to Ethernet 1/0/4 transmit-limit 15
vlan-mapping modulo
Syntax
vlan-mapping modulo modulo
View
MST region view
Parameters
modulo: Modulo by which VLANs are mapped to MSTIs, in the range of 1 to 16.
Description
Use the vlan-mapping modulo command to set the modulo by which VLANs are mapped to MSTIs.
By default, all VLANs in a network are mapped to the CIST (MSTI 0).
MSTP uses a VLAN-to-instance mapping table to describe VLAN-to-instance mappings. You can use
this command to establish the VLAN-to-instance mapping table and map VLANs to MSTIs in a specific
way.
Note that a VLAN cannot be mapped to multiple different MSTIs at the same time. A VLAN-to-instance
mapping becomes invalid when you map the VLAN to another MSTI.
You can map VLANs to the specific MSTIs rapidly by using the vlan-mapping modulo modulo
command. The ID of the MSTI to which a VLAN is mapped can be figured out by using the following
formula:
In this formula, (VLAN ID-1) % modulo yields the module of (VLAN ID-1) with regards to the modulo
argument. For example, if you set the modulo argument to 16, then VLAN 1 is mapped to MSTI 1, VLAN
2 is mapped to MSTI 2, ..., VLAN 16 is mapped to MSTI 16, VLAN 17 is mapped to MSTI 1, and so on.
Related commands:
region-configuration.
Examples
# Map VLANs to MSTIs, with the modulo being 16.
<Sysname> system-view
System View: return to User View with Ctrl+Z.
(VLAN ID-1) % modulo + 1.
check region-configuration,
1-44
revision-level, region-name, active