root@dco:~$ BROWSER > https://www.wireshark.org/docs/dfref > CTRL+F
search: dhcp
https://www.wireshark.org/docs/dfref/d/dhcp.html
root@dco:~$ BROWSER > https://www.wireshark.org/docs/dfref/d/dhcp.html > CTRL+F
search: hostname
dhcp.option.hostname Host Name Character string 3.0.0 to 4.4.5
root@dco:~$ tshark -r hostnames.pcapng -T fields -e dhcp.option.hostname | awk NF | sort -r | uniq -c
1 90-tasd-new
1 mailroom2
2 11-amf-sec
2 205-kaps
2 209-SSW
* the "awk NF" in the pipeline will remove empty lines.
