Reference Guide

Interface
Name Role PortID Prio Cost Sts Cost Link-type Edge
--------------------------------------------------------------
ethernet1/1/5 Root 128.276 128 500 FWD 0 AUTO No
ethernet1/1/6 Altr 128.280 128 500 BLK 0 AUTO No
Non-Dell hardware
OS10 supports only one MST region. For a bridge to be in the same MST region as another, the three unique attributes (name,
revision, and VLAN-to-instance-mapping) must match. The default values for name and revision number match on all Dell
hardware. If you have non-Dell hardware that participates in MST, ensure these values match on all devices.
A region is a combination of three unique attributes:
● Name — A mnemonic string you assign to the region (default is the system MAC address).
● Revision — A 2-byte number (default is 0).
● VLAN-to-instance mapping — Placement of a VLAN in an MSTI.
Region name or revision
You can change the MSTP region name or revision.
● Change the region name in MULTIPLE-SPANNING-TREE mode (up to 32 characters).
name name
● Change the region revision number in MULTIPLE-SPANNING-TREE mode (0 to 65535, default 0).
revision number
Configure and verify region name
OS10(conf-mstp)# name my-mstp-region
OS10(conf-mstp)# do show spanning-tree mst config
MST region name: my-mstp-region
Revision: 0
MSTI VID
1 100
2 200-300
Modify parameters
The root bridge sets the values for forward-delay, hello-time, max-age, and max-hops and overwrites the values set on other
MST bridges.
Forward-time
Time an interface waits in the Discarding state and Learning state before it transitions to the Forwarding
state.
Hello-time Interval in which the bridge sends MST BPDUs.
Max-age Length of time the bridge maintains configuration information before it refreshes that information by
recomputing the MST topology.
Max-hops Maximum number of hops a BPDU travels before a receiving device discards it.
Dell EMC recommends that only experienced network administrators change MST parameters. Poorly planned modification of
the MST parameters can negatively affect network performance.
1. Change the forward-time parameter in CONFIGURATION mode (4 to 30, default 15).
spanning-tree mst forward-time seconds
Layer 2
199