From https://kb.isc.org/docs/isc-dhcp-44-manual-pages-dhcpd#PORTS
( with TCP and imcp port bits cut out:)
Normally a DHCPv4 server will open a raw UDP socket to receive and send most DHCPv4 packets. It also
opens a fallback UDP socket for use in sending unicast packets. Normally these will both use the
well known port number for BOOTPS.
...
For DHCPv6 the server opens a UDP socket on the well known dhcpv6-server port.
...
When DDNS is enabled at compile time (see includes/site.h) the server will open both a v4 and a v6
UDP socket on random ports, unless DDNS updates are globally disabled by setting ddns-update-style
to none in the configuration file.
,.,.
Not best practice to listen on ports when not used .. should be part of the config -- but an
upstream issue.
Karl Schmidt EMail k...@lrak.net
3209 West 9th Street Ph (785) 979-8397
Lawrence, KS 66049
Life is so short, precious, and delicate. All we have is a bit of time.
Best not to waste it. -kps
Carpe diem -- Horace - from 'Carpe diem quam minimum credula postero'
