Network OS Administration Guide

Supporting Network OS 6.0.1a

Part Number: 53-1003768-04

Automatic Login Balancing mode

Automatic Login Balancing (LB) mode works to distribute logins across all available N_Ports in a port group. It is enabled by default when a port group is created.

Consider the following for LB mode:
  • When LB mode is disabled for a port group, the same configured VF_Port to N_Port mapping displays for the show running-config ag or show ag commands. This is because configured and active mapping are the same.
  • When LB mode is enabled for a port group, the show ag command displays the current, active mapping because VF_Port to N_Port mapping is based on the current distributed load across all N_Ports. The show running-config ag command displays the configured mapping only.
  • If LB mode is enabled for a port group and a new N_Port comes online, existing logins are undisturbed. If an N_Port is disabled, its existing logins are distributed to available ports to maintain a balanced N_Port-to-VF_Port ratio.
  • LB can be disabled using Network OS commands. When LB mode is disabled, VF_Ports are not shared among N_Ports in the port group, but can only connect to N_Ports to which they are mapped. If an N_Port is disabled, ENodes logged into mapped VF_Ports log out. As a best practice to ensure device login, bind the ENode to a VF_Port and ensure that its mapped N_Port is online.
  • LB mode is disruptive.
  • If an N_Port is removed from a port group enabled for LB mode and moved to another port group, the VF_Ports mapped to that N_Port remain with the N_Port.

    This is not the case for port groups not enabled for LB mode. When you remove an N_Port from one of these port groups, the VF_Ports mapped to the N_Port move to the default Port Group 0 along with the N_Port. You can then move the N_Port to another group, but would need to re-map any VF_Ports to the N_Port.

  • If an N_Port is in a port group and then Automatic Login Balancing is enabled, the VF_Ports mapped to the N_Port are distributed among online N_Ports in the same port group.
  • You can disable or enable LB mode using the no modes lb or modes lb commands while in the port group configuration mode. Refer to Enabling and disabling Login Balancing mode.