I have been working with setting up an NTP server for testing IPv6 syncing. I am unable to find any help with getting the configuration to work.
If ntp 4.2.6 and ntpdate 4.2.6 say they support IPv6, why is there no documentation explaining what needs to be done to get it working.
My config:
fe80:1000:2000:3000::1/64. = NTP server
NTP servers interface:
2: eth0: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc mq state UP group default qlen 1000
link/ether 00:50:56:92:18:07 brd ff:ff:ff:ff:ff:ff
inet 10.30.15.1/16 brd 10.30.255.255 scope global noprefixroute eth0
valid_lft forever preferred_lft forever
inet6 fe80:1000:2000:3000::1/64 scope link noprefixroute
valid_lft forever preferred_lft forever
inet6 fe80::250:56ff:fe92:1807/64 scope link noprefixroute
valid_lft forever preferred_lft forever
ntp.conf without comments =
driftfile /var/lib/ntp/drift
restrict default nomodify notrap nopeer noquery
restrict -6 default nomodify notrap nopeer noquery
restrict 127.0.0.1
restrict ::1
server 0.centos.pool.ntp.org iburst
server 1.centos.pool.ntp.org iburst
server 2.centos.pool.ntp.org iburst
server 3.centos.pool.ntp.org iburst
includefile /etc/ntp/crypto/pw
keys /etc/ntp/keys
disable monitor
fe80:1000:2000:3000::2 = Client
ntp.conf without comments =
driftfile /var/lib/ntp/drift
restrict 127.0.0.1
restrict ::1
server -6 fe80:1000:2000:3000::1
server -6 DNS-NTP.example.com
includefile /etc/ntp/crypto/pw
keys /etc/ntp/keys
disable monitor
I know we can resolve the IP -> Hostname and Hostname -> IP
[root@ClientIPv6 ~]# nslookup -query=aaaa = DNS-NTP.example.com
Server: fe80:1000:2000:3000::1
Address: fe80:1000:2000:3000::1#53
DNS-NTP.example.com has AAAA address fe80:1000:2000:3000::1
[root@ClientIPv6 ~]# nslookup -query=aaaa fe80:1000:2000:3000::1
Server: fe80:1000:2000:3000::1
Address: fe80:1000:2000:3000::1#53
1.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.3.0.0.0.2.0.0.0.1.0.8.e.f.ip6.arpa name = DNS-NTP.example.com.
ntpdate and ntpq -pn dont show time being synced.
[root@ClientIPv6 ~]# ntpdate -6 -q DNS-NTP.example.com
Error resolving DNS-NTP.example.com: Name or service not known (-2)
31 Jan 13:23:14 ntpdate[25967]: Can't find host DNS-NTP.example.com: Name or service not known (-2)
31 Jan 13:23:14 ntpdate[25967]: no servers can be used, exiting
[root@ClientIPv6 ~]# ntpdate -6 -q fe80:1000:2000:3000::1
31 Jan 13:23:23 ntpdate[25971]: no servers can be used, exiting
This shows the IPv4 address working but the IPv6 does not. (10.30.15.1 is the DNS-NTP.example.com address on the same interface as the IPv6 one…)
[root@ClientIPv6 ~]# ntpq -pn
remote refid st t when poll reach delay offset jitter
==============================================================================
10.30.15.1 200.160.0.8 3 u - 64 1 0.122 -42.146 0.000
fe80:1000:2000: .INIT. 16 - - 64 0 0.000 0.000 0.000
There is no firewall on either server to stop the traffic.
My guess is there is some special way to config ntp.conf but i cant find it online at all.
Can someone please help? Let me know if there is any other info that will help.
Best Answer
For those of you following along, i needed to change the address as pointed out by Ron Maupin.
I changed all the IPs to be in the fddb:abe7:8164:14eb::/64 space and all is working with the above config.