Question is: How can I permanently change my USB tethering IP address? Using Android 11 with a known problem of changing IPs. Only answer I found is How can I permanently change my hotspot tethering IP address? by @irfan-latif . It would be best to comment there, but I do not have 50 points...
Problem is that I could not make fixed Android IP when tethering USB. I have rooted Andorid with Magisk, which I understood is a requirement. With Method 2, I added to /etc/init/usbd.rc (there it is said any .rc file) this, changing to rndis0:
on property:init.svc.hostapd=running
exec - -- /system/bin/sleep 2
exec u:r:magisk:s0 -- /system/bin/ip address add 192.168.43.100/24 dev rndis0
But I do not see it working, also 'ip address' on Android does not show that range. Note: there is a related question at How to make Ethernet work on Android over OTG?.
Anyone may also help with mentioning this question there, hopefully mr. Latif would notice.