Thanks for your answer.
I have checked and actually the DHCP is running correctly releasing an IP
Bottom the console output

Configuring (net2 52:54:00:17:20:11)....ok
net2: 172.17.13.201/255.255.255.0 gw 172.17.13.1
Filename: pxelinux.0
Nothing to boot: No such file or directory (http://ipxe.org/2d03e13b)
No more network devices


Problem is then moved to the tftp booting
I cannot see any entry in the /var/log/messages file of deploy node about the tftp.

In the /srv/tftpboot are present the files

r--r--r-- 1 tftp tftp 76547780 initrd
r--r--r-- 1 tftp tftp 6856480 linux
r--r--r-- 1 tftp tftp 438 messages
rw-r--r-- 1 tftp tftp 26748 pxelinux.0


and directory pxelinux.cfg with the default file inside.

Where I can investigate?
Thanks for any suggestions
Gabriele