I have 20 Raspberry Pi 5B's, and 19 of them are requesting their own IPv6 address every half hour from the Pi-hole.
I cannot work out why only 19 of 20 are doing this as they are all meant to be configured the same.
Does anyone know why the 19 are requesting their own IPv6 address' every 30 minutes, and why one isn't?
No one will be able to answer your question or guess what is happening without more information.
Are you sure they are configured exactly the same?
Other possible questions:
Which OS?
Did you search for similar issues on the OS forums? What did you find?
Are they all on the same subnet?
What is your DHCP server?
One of the Raspberry Pis? or the router? Brand/Model?
Do you have just one DHCP or more than one?
Are you sure this specific device doesn't have a static IP set on the OS?
Please add some context for other users know where to start .
64-bit Pi OS lite
Yes. Nothing.
Yes
Pi-hole
Just one.
All 20 have a static IPv4 address, as they network boot, with the IPv4 address and other network details set in the /boot/firmware/cmdline.txt file. See below.
ip=<IPv4 address>:<TFTP server>:<gateway>:<subnet mask>:<FQDN hostname>:<device>:<autoconfiguration option>, off = no IPv6:<DNS server 1>:<DNS server 2>:<NTP server>
I discovered that the one Pi not requesting it's own IPv6 address, didn't have Network Manager running. For some reason it wasn't starting when the Pi booted, even though it was enabled!
Uninstalling and reinstalling Network Manager fixed that problem.
But, why were devices requesting their own IPv6 address from the Pi-hole. It's their own address, so they should already know it, shouldn't they?