System:communicate:ethernet:whitelist#:Smask; System:communicate:ethernet:reset; System:communicate:ethernet:restart - Keysight N774 C Series Programming Manual

3 Instrument Setup and Status
Parameters: Int (1-10)
Response: IP Address String
Example: :syst:comm:eth:whitel1:smas? -> "192.168.0.2"
Command:

:SYSTem:COMMunicate:ETHernet:WHITEList#:SMASk

Syntax: :SYSTem:COMMunicate:ETHernet:WHITEList#:SMASk
Description: Define an entry in the device access ip whitelist (up to 10 IP Addresses) of permitted client which could control this
instrument.
Parameters: Subnet Mask String
Response: None
Example: :syst:comm:eth:whitel1:smas "192.168.0.2"
Command:

:SYSTem:COMMunicate:ETHernet:RESet

Syntax: :SYSTem:COMMunicate:ETHernet:RESet
Description: Press the "LAN Reset" Button for a long time has the same effect.
Pressing the "LAN Reset" Button for a short time is the same as system:preset.
DHCP On
AutoIP On
NTP Off
Whitelist Off
Hostname is a concatenation of product number and serial number.
The password for the web based LAN configuration interface is reset to a blank password.
Parameters: None
Response: None
Example: :syst:comm:eth:res
Command:

:SYSTem:COMMunicate:ETHernet:RESTart

Syntax: :SYSTem:COMMunicate:ETHernet:RESTart
Description: Restart the system's network interface with the new parameters.
This command only works if the instrument has a working network connection at the time the command is issued.
If not you either have to wait until the instrument decides on an IP address using AutoIP or reboot the instrument.
56 Keysight N774xC Series Multiport Power Meter Programming Guide