Nsdtool is a toolset of scripts used to detect netgear switches in local networks. The tool contains some extra features like bruteforce and setting a new password.
Netgear has its own protocol called NSDP (Netgear Switch Discovery Protocol), which is implemented to support security tests on the commandline. It is not being bound to the delivered tools by Netgear.
Define your interface and possible delay in the config.ini.
# cat config.ini
SourcePort = 63323 <--- nsdp source
DestPort = 63324 <--- nsdp dest
Interface = eth0 <--- your network interface
DestIP = 255.255.255.255
Delay = 0.01 <--- interval delay