Hello,
today I updated to pihole 6. Previously i used this config to get a simple PXE boot service running for my pis.
'''
enable-tftp
tftp-root=/tftpboot
pxe-service=0,"Raspberry Pi Boot"
'''
How can i create a similar config with pihole 6?
Greetings and thank you in advance
Go to Settings > All Settings > Misc > and enter it into misc.dnsmasq_lines
Found it thank you guys 
Should FTL load additional dnsmasq configuration files from /etc/dnsmasq.d/?
etc_dnsmasq_d = true
This is an other possibility if you want to put your code as a dnsmasq config file and load it on Pi-hole startup.
Both ways should work
good thing is i can see the rainbow splash. Sadly nothing more happens.
Pi does not boot anymore 
setting/misc.dnsmasq_lines
enable-tftp
tftp-root=/tftpboot
# pxe rpi
pxe-service=0,"Raspberry Pi Boot"
The directory is mounted to /tftpboot
Volume=/srv/tftpboot:/tftpboot
[Unit]
Description=pihole container
Wants=network-online.target
After=network-online.target nss-lookup.target
[Container]
Image=docker.io/pihole/pihole:latest
ContainerName=pihole
HostName=pihole.ohs.lan
IP=192.168.2.254
Network=macvlan.network
# extra caps
AddCapability=NET_ADMIN CAP_NET_RAW NET_RAW
# Enable auto-update container
AutoUpdate=registry
Volume=/srv/container/pihole/etc-pihole:/etc/pihole
Volume=/srv/container/pihole/etc-dnsmasq.d:/etc/dnsmasq.d
Volume=/srv/tftpboot:/tftpboot
Environment=TZ=Europe/Berlin
Environment=WEBPASSWORD=piholepw
[Service]
Restart=always
TimeoutStartSec=900
[Install]
WantedBy=default.target
nothing special was configured in previous release i think.
Greetings
This is no longer a valid environment variable, though probably not directly related to your issue.
Yes, the variable will be removed, thank you.
I have seen that there is a migration directory.
etc-pihole/migration_backup_v6
Unfortunately, I have later this day time to compare the configs.
Do you know if there was changes in pihole6 - dnsmasq related to pxe?
Thank you in advance.
From the dnsmasq CHANGELOG:
57 Add --dhcp-option-pxe config. This acts almost exactly like
58 --dhcp-option except that the defined option is only sent when
59 replying to PXE clients. More importantly, these options are sent
60 in reply PXE clients when dnsmasq in acting in PXE proxy mode. In
61 PXE proxy mode, the set of options sent is defined by the PXE standard
62 and the normal set of options is not sent. This config allows arbitrary
63 options in PXE-proxy replies. A typical use-case is to send option
64 175 to iPXE. Thanks to Jason Berry for finding the requirement for
65 this.
66
67 Support PXE proxy-DHCP and DHCP-relay at the same time.
68 When using PXE proxy-DHCP, dnsmasq supplies PXE information to
69 the client, which also talks to another "normal" DHCP server
70 for address allocation and similar. The normal DHCP server may
71 be on the local network, but it may also be remote, and accessed via
72 a DHCP relay. This change allows dnsmasq to act as both a
73 PXE proxy-DHCP server AND a DHCP relay for the same network.
That's it.
@DL6ER i dont know how to set dhcp-option-pxe and tried various things.
So far I had no luck to get pxe running with v6. Pis stuck always @ rainbow splash.
The bootfiles have the correct permissions (chmod -R 755 /srv/tftpboot)
As a workaround the container was downgraded, and pxe worked again like expected
image=docker.io/pihole/pihole:2024.07.0
[Unit]
Description=pihole container
Wants=network-online.target
After=network-online.target nss-lookup.target
[Container]
#Image=docker.io/pihole/pihole:latest
Image=docker.io/pihole/pihole:2024.07.0
ContainerName=pihole
HostName=pihole.ohs.lan
IP=192.168.2.254
Network=macvlan.network
AddCapability=CAP_NET_ADMIN CAP_NET_RAW CAP_NET_BIND_SERVICE CAP_CHOWN
AutoUpdate=registry
Volume=/srv/container/pihole/etc-pihole:/etc/pihole
Volume=/srv/container/pihole/etc-dnsmasq.d:/etc/dnsmasq.d
Volume=/srv/tftpboot:/tftpboot
Environment=TZ=Europe/Berlin
Environment=WEBPASSWORD=piholepw
[Service]
Restart=always
TimeoutStartSec=900
[Install]
WantedBy=default.target
Thanks @ all so far
Do you have any related logs from /var/log/pihole/pihole.log ?
It'd also be worth using some tool like tcpdump to record a pcap from the working and the non-working containers so we can do an in-depth debugging looking at the differences between the two.
When passing some DHCP Options like 43 for example you need to encode the stuff you are sending to the Client in a certain format : Maybe you need to do this too from now on ?!
/Very wild guess...