IBM RackSwitch G8000, Application Manual

Page: 131 / 362

© Copyright IBM Corp. 2011 Chapter 10. Spanning Tree Protocols
129
Tree priority values are configured so that each routing switch is the root for a
different MSTP instance. All of the uplinks are active, with each uplink port backing
up the other.
1. Configure port membership and define the STGs for VLAN 1. Enable tagging
on uplink ports that share VLANs. Port 19 and port 20 connect to the Enterprise
Routing switches.
2. Add server ports 1 and 2 to VLAN 1. Add uplink ports 19 and port 20 to VLAN 1.
3. Configure MSTP: Spanning Tree mode, region name, and version.
4. Configure port membership and define the STGs for VLAN 2. Add server
ports 3, 4, and 5 to VLAN 2. Add uplink ports 19 and 20 to VLAN 2. Assign
VLAN 2 to STG 2.
Note: Each STG is enabled by default.
Port Type and Link Type
Edge Port
A port that does not connect to a bridge is called an edge port . Since edge ports are
assumed to be connected to non-STP devices (such as directly to hosts or servers),
they are placed in the forwarding state as soon as the link is up.
Edge ports send BPDUs to upstream STP devices like normal STP ports, but do not
receive BPDUs. If a port with
edge
enabled does receive a BPDU, it immediately
begins working as a normal (non-edge) port, and participates fully in Spanning Tree.
Use the following commands to define or clear a port as an edge port:
RS G8000(config)#
interface port 19
RS G8000(config-if)#
tagging
RS G8000(config-if)#
exit
RS G8000(config)#
interface port 20
RS G8000(config-if)#
tagging
RS G8000(config-if)#
exit
RS G8000(config)#
vlan 1
RS G8000(config-vlan)#
enable
RS G8000(config-vlan)#
member 1,2,19,20
RS G8000(config-vlan)#
stg 1
RS G8000(config-vlan)#
exit
RS G8000(config)#
spanning-tree mstp name MyRegion
RS G8000(config)#
spanning-tree mode mst
RS G8000(config)#
spanning-tree mstp version 100
RS G8000(config)#
vlan 2
RS G8000(config-vlan)#
enable
RS G8000(config-vlan)#
member 3,4,5,19,20
RS G8000(config-vlan)#
stg 2
RS G8000(config-vlan)#
exit
RS G8000(config)#
interface port
<port>
RS G8000(config-if)# [
no
]
spanning-tree edge
RS G8000(config-if)#
exit