Cisco MDS / Nexus. Track down where a wwpn is logged in

Low effort post, this is more for my own reference, but if someone else finds it useful then great!

*unfortunately I dont have a great reference for this as I dont have access to a good mds/san lab environment. 

Assuming you know the pwwn of the device your looking for. 

where {p} will act as a variable for the pwwn, and {f} will act as a variable for the FCID

Show fcns database 

or if you know the vsan it should belong to 

show fcns database vsan x

You can also filter assuming you know the pwwn 

show fcns database | i {p}

show fcns database vsan x | i {p}

For each configured vsan, and grouped by each vsan, this output will give you the following output

FCID | Type | PWWN | Vendor | FC4-TYPE FEATURE

Make note of the FCID and vsan the pwwn is configured under. and enter the following command. 

* where {f} is acting as a variable for the FCID. 

show fcns database fcid {f} detail vsan x

At the very bottom of this output you should see two fields. 

Connected interface: 

switch name (IP address):

This should be where your pwwn is physically connected.