bin/164348: ntp.conf restrict default ignore option doesn't
function as advertised
yanegomi at gmail.com
Sat Jan 21 09:20:06 UTC 2012
>Synopsis: ntp.conf restrict default ignore option doesn't function as advertised
>Arrival-Date: Sat Jan 21 09:20:06 UTC 2012
>Originator: Garrett Cooper
FreeBSD bayonetta.local 9.0-STABLE FreeBSD 9.0-STABLE #4 r230371M: Thu Jan 19 23:55:38 PST 2012 gcooper at bayonetta.local:/usr/obj/store/freebsd/stable/9/sys/BAYONETTA amd64
While trying to lock down ntpd without a firewall, I was trying to do one of two things:
1. Get ntpd to listen only on localhost to avoid opening up potential security backdoors.
2. Get ntpd to listen to a select set of addresses.
Point was to get ntpd to function in a 'more secure' manner like ntpdate.
It doesn't seem that there's a 'listen only on select addresses option' available in ntpd, so 1. looks impossible. According to the documentation though, I should be able to restrict access to just localhost, so 2. should be doable . In reality, this option doesn't seem to work as advertised, s.t. if I set 'restrict ignore default' it will reject all requests.
# cat > /etc/ntp.conf <<EOF
server 0.freebsd.pool.ntp.org iburst maxpoll 9
server 1.freebsd.pool.ntp.org iburst maxpoll 9
server 2.freebsd.pool.ntp.org iburst maxpoll 9
restrict default ignore
restrict -6 ::1
# service ntpd restart
More information about the freebsd-bugs