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I created a Pi-hole on a Raspberry PI running Raspbian Stretch Lite, and set a static IP of 10.0.10.10, works for about a week. Expectation is that 10.0.10.10 is always going to be the STATIC IP. My PFSense DHCP server provides this address to all DHCP requests.
After about a week, Raspbian Lite pulls a DHCP address of 10.0.10.104 (in my DHCP scope). The web gui for Pi-hole shows 10.0.10.10 as the IP address and when I SSH into the Raspberry Pi running Raspbian Lite, and run IP ADDR, it shows 10.0.10.104 as the ETH0 IP! Also, /etc/dhcpcd.conf shows the proper information of 10.0.10.10 for the ETH0 interface.
/etc/network/interfaces simply says:
# interfaces(5) file used by ifup(8) and ifdown(8)
# Please note that this file is written to be used with dhcpcd
# For static IP, consult /etc/dhcpcd.conf and 'man dhcpcd.conf'
# Include files from /etc/network/interfaces.d:
I have run updates and upgrades, as well as pihole -up. I have also done numerous pihole -r attempts with reconfigure but still get the 10.0.10.104 address no matter how many times i tell the wizard I want 10.0.10.10. to be the static IP.