I have to configure NTP on a CentOS server. I have 7 interfaces and I can reach the NTP server through one interface. Also the server doesn't have access to internet.
When I try ping:
ping 10.0.10.12
connect: Network is unreachable
But when I ping with source interface, the ping is successful.
ping -I eth0 10.0.10.12
PING 10.0.0.131 (10.0.10.12) from 10.69.4.16 eth0: 56(84) bytes of data.
64 bytes from 10.0.10.12: icmp_seq=1 ttl=127 time=4.07 ms
64 bytes from 10.0.10.12: icmp_seq=2 ttl=127 time=0.309 ms
64 bytes from 10.0.10.12: icmp_seq=3 ttl=127 time=0.318 ms
ntpstat command output:
unsynchronised
time server re-starting
polling server every 8s
ntpq -p command output:
remote refid st t when poll reach delay offset jitter
==============================================================================
10.0.10.12 .INIT. 16 - - 512 0 0.000 0.000 0.000
I also tried ntpdate – d 10.0.10.12:
ntpdate -d 10.0.0.131
23 Jul 09:14:31 ntpdate[16715]: ntpdate 4.2.6p5@1.2349-o Sat Nov 23 18:21:48 UTC 2013 (1)
Looking for host 10.0.0.131 and service ntp
host found : 10.0.0.131
23 Jul 09:14:31 ntpdate[16715]: no servers can be used, exiting
The NTP server is configured in the ntp.conf file, I think that the problem is something with the network. I was wondering if I can make explicit source interface for reaching the NTP server?
Best Answer
You can add a specific host route for your NTP server:route add -host 10.0.10.12 dev eth0
, for example.As per Anton's completely correct comment, here is the command in
iproute2
syntax:ip route add 10.0.10.12 dev eth0