[pkg-dhcp-devel] Bug#712503: dhcpd is listening on random port for all interfaces

[Sergey B Kirpichev]

Package: isc-dhcp-server
Version: 4.2.2.dfsg.1-5+deb70u6
Severity: important
Tags: security

Actually, there are two issues:
1) dhcpd is listening on random port (UDP) for all interfaces, no
   configuration option or CLI switch can fix with this situation.
2) moreover, dhcpd is listening for UDPv6 too, even if you include -4
   option for dhcpd:

$ cat /etc/default/isc-dhcp-server | sed '/^$/d;/^#/d'
INTERFACES="br0"
OPTIONS="-4"
$ ps w 15686
  PID TTY      STAT   TIME COMMAND
15686 ?        Ss     0:00 /usr/sbin/dhcpd -q -4 -cf /etc/dhcp/dhcpd.conf -pf /var/run/dhcpd.pid br0
$ netstat -tulp
[...]
udp        0      0 *:9922                  *:*                                 15686/dhcpd
udp        0      0 home.test:domain        *:*                                 4832/named
udp        0      0 home.test:bootps        *:*                                 15686/dhcpd
udp6       0      0 [::]:37045              [::]:*                              15686/dhcpd

PS: See also http://forums.debian.net/viewtopic.php?f=10&t=95273