Specifications

8-36 Rapier Switch Software Reference
Software Release 2.7.3
C613-03098-00 REV A
If creating multiple STPs in a network, consider the following:
• A VLAN can only belong to a single STP.
• Except on the Rapier i Series switches, any port in the switch must
belong only to a single STP. When a port is a member of multiple
VLANs, all these VLANs must belong to the same STP. Within any
given STP, all VLANs belonging to it use the same Spanning Tree. On
the Rapier i Series switches only, a port can belong to multiple STPs
when the port is a member of more than one VLAN.
Overlapping VLANs belonging to Multiple
Spanning Tree Instances
The Rapier i Series switch supports cases where a port can be in more than one
Spanning Tree instance when the port is a member of more than one VLAN
and those VLANs belong to different STPs (Figure 8-5 on page 8-36).
On the Rapier i Series switches only, the number of STPs that can be configured
is 255.
Figure 8-5: Port membership of VLANs which belong to different spanning tree instances (on Rapier i Series switches only)
Configuring STP
By default, the switch has one default STP which cannot be destroyed. In most
situations this default STP suffice. However, further instances of the Spanning
Tree Protocol (STPs) can be created and destroyed using the commands:
create stp=stp-name
destroy stp={stp-name|all}
STP A
STP B
VLAN 1
VLAN 2
VLAN 3
Port 1
Port 2
Port 3
Port 2 is a member of multiple Spanning Tree Instances (STP A and STP B) because it is a member of
multiple VLANs (VLAN 2 and VLAN 3).
SWITCH12