From af1c2552f151bd5a30ecc5257edb632852ec92ee Mon Sep 17 00:00:00 2001 From: delphij Date: Fri, 27 Dec 2013 23:13:38 +0000 Subject: [PATCH] MF10 r259974 (MFC r259973): Tighten default restrictions for ntpd(8) server and provide a link to NTP access restriction documentation. Approved by: re (gjb) git-svn-id: svn://svn.freebsd.org/base/releng/10.0@259975 ccf9f872-aa2e-dd11-9fc8-001c23d0bc1f --- etc/ntp.conf | 34 +++++++++++++++++++++++++--------- 1 file changed, 25 insertions(+), 9 deletions(-) diff --git a/etc/ntp.conf b/etc/ntp.conf index 0421e4c2..8419adf5 100644 --- a/etc/ntp.conf +++ b/etc/ntp.conf @@ -17,7 +17,7 @@ # users with a static IP and good upstream NTP servers to add a server # to the pool. See http://www.pool.ntp.org/join.html if you are interested. # -# The option `iburst' is used for faster initial synchronisation. +# The option `iburst' is used for faster initial synchronization. # server 0.freebsd.pool.ntp.org iburst server 1.freebsd.pool.ntp.org iburst @@ -35,21 +35,37 @@ server 2.freebsd.pool.ntp.org iburst # server 2.CC.pool.ntp.org iburst # -# Security: Only accept NTP traffic from the following hosts. -# The following configuration example only accepts traffic from the -# above defined servers. +# Security: +# +# By default, only allow time queries and block all other requests +# from unauthenticated clients. +# +# See http://support.ntp.org/bin/view/Support/AccessRestrictions +# for more information. +# +restrict default kod nomodify notrap nopeer noquery +restrict -6 default kod nomodify notrap nopeer noquery +# +# Alternatively, the following rules would block all unauthorized access. +# +#restrict default ignore +#restrict -6 default ignore +# +# In this case, all remote NTP time servers also need to be explicitly +# allowed or they would not be able to exchange time information with +# this server. # # Please note that this example doesn't work for the servers in # the pool.ntp.org domain since they return multiple A records. -# (This is the reason that by default they are commented out) # -#restrict default ignore #restrict 0.pool.ntp.org nomodify nopeer noquery notrap #restrict 1.pool.ntp.org nomodify nopeer noquery notrap #restrict 2.pool.ntp.org nomodify nopeer noquery notrap -#restrict 127.0.0.1 -#restrict -6 ::1 -#restrict 127.127.1.0 +# +# The following settings allow unrestricted access from the localhost +restrict 127.0.0.1 +restrict -6 ::1 +restrict 127.127.1.0 # # If a server loses sync with all upstream servers, NTP clients -- 2.42.0