Gateway IP address of NTP server. Only necessary if NTP server is in different subnet than device and needs to be accessed through a gateway. Otherwise can be left as 0
The first octet of the IP address is placed in the least significant byte of the u32.
For example, the IP address 192.168.2.2 would be packed into a u32 like this:
u32 ip = (192) | (168 << 8) | (2 << 16) | (2 << 24);