How to give static ip to my usb drive on my network? It is connected to my router (usb 3.0). Whenever the router is restarted the IP changes and I always have to change the IP in my phone for backup.
and the router is access point mode, as it is connected to my main basic optic fibre router given by my network provider.
Terminology: A "static" address is configured on the device itself. What you configure on a (DHCP server on a) router is a reserved dynamic address, not a static address. Either one should fix the address of a device, but some implications are different.
A USB storage device does not have an IP address.
> [...] It is connected to my router (usb 3.0). [...]
Your "my router" should have a LAN IP address.
> Model: R6400|AC1750 Smart WiFi Router
That's your "my router"? R6400[v1] or R6400v2? Look for "Model" on the product label.
> [...] the router is access point mode, as it is connected to my main > basic optic fibre router given by my network provider.
When you configure an R6400[vX] as a wireless access point, it should, by default, get a new/different LAN IP address from your main router, using DHCP. If you want it to get the same IP address every time, then you'd probably want to arrange an address reservation (with the DHCP server) in your (unspecified) "my main basic optic fibre router given by my network provider", about which I know nothing.
