Rejecting Duplicate Pwwns; Name Server Database Entries - Cisco Nexus 6000 Series Configuration Manual

Managing FLOGI, Name Server, FDMI, and RSCN Databases
If you disable this option, any future flogi (with duplicate pwwn) on different switch in the same VSAN,will
be allowed to succeed by deleting earlier FCNS entry.

Rejecting Duplicate pWWNs

By FC standard, NX-OS will accept a login on any interface of a pwwn that is already logged in on the same
switch, same vsan, same fcdomain. To prevent the same pwwn from logging in the same switch on a different
interface, use the port security feature.
By default, any future flogi (with duplicate pwwn) on different switch in the same vsan, will be rejected and
earlier FLOGI retained, which does not follow FC standards.
If you disable this option, any future flogi (with duplicate pwwn) on different switch in the same VSAN,will
be allowed to succeed by deleting earlier FCNS entry.
To reject duplicate pWWNs, follow these steps:
Procedure
Step 1
Step 2
Step 3

Name Server Database Entries

The name server stores name entries for all hosts in the FCNS database. The name server permits an Nx port
to register attributes during a PLOGI (to the name server) to obtain attributes of other hosts. These attributes
are deregistered when the Nx port logs out either explicitly or implicitly.
In a multiswitch fabric configuration, the name server instances running on each switch shares information
in a distributed database. One instance of the name server process runs on each switch.
OL-27932-01
Command or Action
configure terminal
Example:
switch# configure terminal
switch(config)#
fcns reject-duplicate-pwwn vsan vsan-id
Example:
switch(config)# fcns
reject-duplicate-pwwn vsan 100
no fcns reject-duplicate-pwwn vsan vsan-id
Example:
switch(config)# no fcns
reject-duplicate-pwwn vsan 256
Cisco Nexus 6000 Series NX-OS SAN Switching Configuration Guide, Release 6.x
Name Server Proxy
Purpose
Enters global configuration mode.
Any future flogi (with duplicate pwwn) on different
switch, will be rejected and earlier FLOGI retained
(default).
Any future flogi (with duplicate pwwn) on different
switch, will be allowed to succeed by deleting
earlier FCNS entry.
But you can still see the earlier entry in FLOGI
database in the other switch.
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