In the past I mostly used tcptraceroute to check http and ssh.
Now I need to check if my host can reach the NTP server.
Is this possible at all?
I have two machines.
At application level I see: Machine qual can't reach the ntp server, and machine prod can reach the ntp server.
If I run this command, the output of both is equal:
Prod:
prod:(/root/home/root)(root)#traceroute -U -p ntp 30.252.33.1
traceroute to 30.252.33.1 (30.252.33.1), 30 hops max, 60 byte packets
1 * * *
2 * * *
3 * * *
4 * * *
5 * * *
6 * * *
7 * * *
Qual:
qual:~ # traceroute -U -p ntp 30.252.33.1
traceroute to 30.252.33.1 (30.252.33.1), 30 hops max, 60 byte packets
1 * * *
2 * * *
3 * * *
4 * * *
5 * * *
6 * * *
7 * * *
I guess the NTP server just drops the UDP packages from traceroute, and traceroute receives not answer.
(for TCP based services this works fine, since there is some "connection established" reply).
Is it possible to check ntp at network level with networking tools like traceroute?
If not, how to check if a machine can reach the ntp server?