API Guide

response change to the unstable state. The sessions keep flapping until the request and response converge in the same port. To
avoid this, pin one of the ports in the port-channel.
To support FCoE on multi-level VLT networks, use port pinning in FCoE LAGs. Port pinning is a static configuration that
restricts the FIP and FCoE traffic to one port of the port-channel overriding hardware LAG hashing. The system classifies and
redirects the packets exchanged during FCoE sessions to the port based on the ACL configuration. The remaining Ethernet
traffic flows through both the pinned port and other ports in the port-channel, based on LAG hashing. Dell EMC recommends to
use pinned port if there are more than one port in FCoE LAG. In a VLT network, the server has two unique FCoE sessions to
SAN fabric and the traffic flows based on pinned port configuration. If there is only one port in the port-channel, there is no
need for a pinned port.
NOTE: The pinned port configuration is supported on FSB, Ethernet downlink port-channel of NPG, and F_Port mode.
Limitations:
● The system uses an ACL table for ENode MAC with a redirect port option similar to FCF. This limits the number of FC or
FCoE sessions.
● When the pinned port goes down, you must manually re-configure another active port in the port-channel as pinned port.
You can perform this re-configuration only in the intermediate switches, but not in the server.
● If there is a mismatch in the configuration or if the pinned port goes down, the system does not use other ports in port-
channel even if there is a valid path to server and storage device.
● When you add or remove a pinned port when FCoE sessions are active, the system clears and re-initiates the FCoE sessions
based on the configuration. The system displays warning messages during the configuration.
The following illustrations show VLT and non-VLT networks with FCoE traffic flowing through pinned port.
334 Fibre Channel