I start by saying that my experience in networking is somewhere between low and medium.
I'm working on a Linux machine with DHCP configured and from tcpdump traces I see that the dhclient send the hostname "linux" in Option 12, Request packages. I verified the files /etc/hostname, /etc/hosts and /etc/dhclient.conf and there's no parameter related to the hostname that have the value "linux". I must specify that I use dhcpcd.
Any help/hint is appreciated since I don't have any ideas where that value is set.