Recommendations for Configuring Stacks

When deploying a new stack, follow these recommendations for configuring the software:

• Plan to use the stack as if it were a single multi-slot switch. You need to decide the number and type of stackable switches in the stack and how the stack ports will be connected to the network.
• You can physically connect the stack to your networks before the nodes are configured. However, the default configuration on a switch in non-stacking mode assumes a default untagged VLAN that contains all switch ports. When first powered on, the switch acts as a Layer 2 switch, possibly resulting in network loops.
• Make sure all nodes support the SummitStack feature and are running the same Switch Engine software version. (See the Switch Engine 32.1 Feature License Requirements .) To view the Switch Engine software version on a node, restart the node and run the command:

  show version {detail | process name | images {partition partition} {slot slot_number} } .

  If any node does not have the right version, install the correct version on that node. Use the same image partition on all nodes. After stacking is enabled, images can be upgraded from the stack only if the same image is selected on all nodes.

• If you intend to deploy new units that might be part of a stack in the future, turn on stacking mode during initial deployment to avoid the need for a future restart. The only disadvantages of stacking mode are the loss of QoS (quality of service) profile QP7 and the reservation of some of the packet buffer space for stacking control traffic.
• You can configure the stack by logging into the primary node or any of the other nodes.
• If the primary-capable stackable switches have different purchased license levels, you might need to configure license level restrictions on some nodes before those nodes can join the stack. See the Switch Engine 32.1 User Guide for more information about managing licenses.
• If the stack supports any feature pack license (such as MPLS or Direct Attach), that feature pack license must be installed on all primary-capable nodes to support that feature and to prevent traffic interruption if a failover event occurs.
• Most stacking specific configurations are effective only after a restart. However, most non-stacking configuration commands take effect immediately and require no restart.
• A basic stack configuration can be achieved by using the Easy Setup procedure, as described in the Switch Engine 32.1 User Guide .
• If EAPS, Spanning Tree, or any Layer 2 redundancy protocol is not running on the network, make sure that your network connections do not form a network loop.

Follow the recommendations in Recommendations for Placing Switches for Stacked Operation for physically situating your equipment.