Cisco ONS 15454 Series Procedure Manual page 226

NTP-A191 Create an E-Series EtherSwitch Circuit (Multicard or Single-Card Mode)
Click Next.
Step 16
In the Circuit VLAN Selection area, click New VLAN. If the desired VLAN already exists, continue
Step 17
with Step
Tip
In the Define New VLAN dialog box, complete the following:
Step 18
VLAN Name—Assign an easily identifiable name to your VLAN.
•
VLAN ID—Assign a VLAN ID. The VLAN ID should be the next available number between 2 and
•
4093 that is not already assigned to an existing VLAN. Each ONS 15454 network supports a
maximum of 509 user-provisionable VLANs.
Topology Host—Choose the topology host ID from the drop-down list.
•
Click OK.
Step 19
In the Circuit VLAN Selection area, highlight the VLAN name and click the arrow button (>>) to move
Step 20
the available VLANs to the Circuit VLANs column.
If you are building a single-card EtherSwitch circuit and want to disable spanning tree protection on this
Step 21
circuit, uncheck the Enable Spanning Tree check box and click OK in the Disabling Spanning Tree
dialog box. The Enable Spanning Tree box remains checked or unchecked for the creation of the next
single-card, point-to-point Ethernet circuit.
Caution Disabling spanning-tree protection increases the likelihood of logic loops on an Ethernet network.
Turning off spanning tree on a circuit-by-circuit basis means that the ONS 15454 is no longer protecting
Caution
the Ethernet circuit and that the circuit must be protected by another mechanism in the Ethernet network.
Multiple circuits with spanning tree protection enabled incur blocking if the circuits traverse the same
Caution
E-Series card and use the same VLAN.
Spanning-tree rules prevent users from creating new circuits or modifying existing circuits if the circuits
Note
do not meet certain VLAN assignment constraints. If the VLAN set of the new circuit overlaps existing
circuits, the same spanning-tree instance is used for all circuits. If the VLAN set of the new circuit
overlaps with VLAN sets of existing circuits with different spanning-tree instances, the VLAN
assignment fails. Cisco recommends that you plan VLAN assignments so that circuits with larger VLAN
sets and a higher chance of overlap are added first. This means that if a circuit with an overlapping
VLAN set is added, it collapses into the same spanning tree. To view circuits mapped to a spanning tree
and their VLAN assignments, see the
You can disable or enable spanning tree protection on a circuit-by-circuit basis only for single-card,
Note
point-to-point Ethernet circuits. Other E-Series Ethernet configurations disable or enable spanning tree
on a port-by-port basis.
Cisco ONS 15454 Procedure Guide, R5.0
6-58
20.
You can also add VLANs in network view by choosing Tools > Manage VLANs. In the All
VLANs dialog box, click the Create button to open the Define New VLAN dialog box.
"DLP-A430 View Spanning Tree Information" task on page
Chapter 6 Create Circuits and VT Tunnels
August 2005
21-9.