Advanced Traffic Management Guide K/KA/KB.15.15

IDF2WEST(config-if-range)#: switchport trunk allowed vlan 1,23-25,27-29
IDF2WEST(config-if-range)#: spanning-tree cost 20000
IDF2WEST(config-if-range)#: exit
Configure MST and enable MSTP globally
IMPORTANT: It is very important that all switch MST configurations match exactly. The name,
revision, and instance VLAN mappings must be identical on all switches participating in MSTP
configuration.
IDF2WEST(config)#: spanning-tree mst configuration
IDF2WEST(config-mst)#: name mstp-vrrp
IDF2WEST(config-mst)#: revision 1
IDF2WEST(config-mst)#: instance 1 vlan 3-5,23-25,33-35,43-45
IDF2WEST(config-mst)#: instance 2 vlan 7-9,27-29,37-39,47-49
IDF2WEST(config-mst)#:exit
IDF2WEST(config)#: spanning-tree mode mst
Edge port configuration
For this configuration no edge ports were configured.
NOTE: If edge ports are not configured, convergence times will slow down drastically.
Below is an example of the commands required to configure a range or individual ports for untagged
VLAN 9. Be sure to edit command for correct ports and VLANS.
IDF2WEST(config)#: interface range fastethernet 0/1-44
IDF2WEST(config-if-range)#: switchport mode access
IDF2WEST(config-if-range)#: switchport access vlan 9
IDF2WEST(config-if-range)#: exit
IDF2WEST(config)#: interface fastethernet 0/1
IDF2WEST(config-if-range)#: switchport mode access
IDF2WEST(config-if-range)#: switchport access vlan 9
IDF2WEST(config-if-range)#: exit
Configure port fast and BPDU guard on edge ports
When configuring an interface with port fast, the edge port immediately transitions to the forwarding
state. Port Fast should be enabled only on ports that connect to a single end station. When you
globally enable BPDU guard on ports that are Port Fast-enabled (the ports are in a Port
Fast-operational state), spanning tree shuts down Port Fast-enabled ports that receive BPDUs. In a
valid configuration, Port Fast-enabled ports do not receive BPDUs. Receiving a BPDU on a Port
Fast-enabled port signals an invalid configuration, such as the connection of an unauthorized
device, and the BPDU guard feature puts the port in the error-disabled state. The BPDU guard
feature provides a secure response to invalid configurations because you must manually put the
port back in service.
IDF2WEST(config)#: spanning-tree portfast bpduguard default
IDF2WEST(config)#: interface range fastethernet 0/1-44
IDF2WEST(config-if-range)#: spanning-tree portfast
IDF2WEST(config-if-range)#: end
NOTE: Never connect LAGs before they are configured. This will create loops in your network
and create an unstable environment.
Configurations 397