Configuration Guide User guide

FastIron Configuration Guide 721
53-1002494-02
Dynamic link aggregation
Configuration notes and limitations for configuring
IronStack LACP trunk groups
This section lists the configuration considerations and limitations for dynamic link aggregation.
FastIron stackable devices
The following notes and feature limitations apply to the FastIron WS and Brocade FCX Series
devices:
• The dynamic link aggregation (802.3ad) implementation allows any number of ports up to
eight to be aggregated into a link.
• The default key assigned to an aggregate link is based on the port type (1 Gbps port or 10
Gbps port). The device assigns different keys to 10 Gbps ports than to 1 Gbps ports so that
ports with different physical capabilities will not be able to form a trunk.
NOTE
The trunks that will be formed by link aggregation will strictly adhere to the static trunking rules
on the stackable devices. Be careful in selecting keys if you are manually configuring link
aggregation keys. Make sure that the possible trunks that you expect to be formed conform to
the static trunking rules.
• When you enable link aggregation (LACP) on a group of Brocade ports, you must also assign a
unique key (other than the default key) to all of the ports in the aggregate link.
FastIron stackable devices in an IronStack
• If a stack unit fails, or is removed from the stack, its LACP configuration becomes a reserved
configuration on the Active Controller. Any remaining ports of the dynamic trunk in the
IronStack continue to function.
• Merging two IronStacks with a dynamic trunk configured between them results in self-looped
ports, which are detected and corrected by the Spanning Tree Protocol (STP).
• When an IronStack with dynamic trunks partitions into multiple IronStacks, the protocol will
take care of splitting the dynamic trunk in the partner. No user intervention is required.