> # About WWN Identification

> If you decide to manually configure port security, be sure to adhere to the following guidelines:

> - Identify switch ports by the interface or by the fWWN.
> - Identify devices by the pWWN or by the nWWN.
> - If an Nx port is allowed to log in to SAN switch port Fx, then that Nx port can only log in through the specified Fx port.
> - If an Nx port’s nWWN is bound to an Fx port WWN, then all pWWNs in the Nx port are implicitly paired with the Fx port.
> - TE port checking is done on each VSAN in the allowed VSAN list of the trunk port.
> - All PortChannel xE ports must be configured with the same set of WWNs in the same PortChannel.
> - E port security is implemented in the port VSAN of the E port. In this case the sWWN is used to secure authorization checks.
> - Once activated, the config database can be modified without any effect on the active database.
> - By saving the running configuration, you save the configuration database and activated entries in the active database. Learned entries in the active database are not saved.

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