@george1421 At last I succeeded to network boot latest Bitdefender Rescue CD
What helped me is when I dropped to the client shell, I saw /lib/modules/$KERNEL/modules.order was listing nfsv3.ko, nfsv4.ko & other .ko files related to nfs, but they were missing in /lib/modules/$KERNEL/fs/nfs & /lib/modules/$KERNEL/fs/nfs_common …
Basically what I did is extract init file (initfs.i386-pc) file provided in Bitdefender’s iso and extract the filesystem (livecd.squashfs)
Then rsync both /lib/modules/$KERNEL/fs/ directories to inject missing .ko files in the initfs, and recompress to a new initfs. Then modify ipxe settings to point to the updated initfs.i386-pc and …
IT WORKED
I guess you can mark this one as solved, if you want I can detail all the steps or provide the working initfs.i386-pc file. Thanks for your support