very strange but this is still saved as ip address even if you enter dns name!
There are three parameters:
- primary-ntp and secondary-ntp - these accept only ip address, if you enter hostname in WinBox, it gets resolved to address
- server-dns-names - if you want to use hostname, put it here
its apparently still need IP addresses to “bootstrap” SNTP client, aside DNS names from ntp pool members, chosen by you to rely on.
which isn’t correct i think too, yep.
What I see here, just server-dns-names alone is enough. But of course you need working dns.
With the real ntp package there are no dns names at all.
server-dns-names
where exactly this parameter is hiding?
not found in sysytem - ntp client.
only two ip addresses there. please implement this as it sholuld be - with dns names support for ntp servers
system ntp client set
enabled mode primary-ntp secondary-ntp
The situation is different when you have installed the ntp package, which you should only install when you want
your MikroTik to be an NTP server for inside equipment. In that case you want fixed external servers that you
can trust and that agree to serve you. These can only be configured with a fixed IP.
When you just want your router to keep the current time for its own use, do not install the ntp package.
You will then get the built-in SNTP client that has the functionality of resolving DNS names that you need.
i think It’s an administrator decision which servers he trust and how he want them to be specified - by name or by ip.
Sure, but the NTP server does not support selecting servers by name and neither does it support resolving DNS
on every poll. That is because an NTP server tries to lock the clock as closely as possible to an external reference,
and that is not possible when the reference changes all the time.
For SNTP it is not a problem, so you can use that for the functionality you require.
I don’t agree.
This is not true. DNS and NTP are not connected. Using name instead of IP address doesn’t reflect on the NTP request.
When you are using name, there is a DNS request first, and then NTP request to the resolved IP address. Thus there is no delay to the NTP communication. It is simply postponed until DNS returns current IP address.
In other words - NTP request is always towards IP address. But DNS guaranties that the IP address will be correct every time.
Using fixed IP addresses may put you in situation in which both servers are down (not very likely, but still possible) and you can’t obtain current time.
That is the meaning of NTP pools. And in other hand - it distributes requests between servers to equalize the load, since it returns different address every time.
This is a change in functionality for the NTP server. The reference ntpd that is probably used inside RouterOS
traditionally did not allow this, so probably the used version is still from that time. DNS names were supported
but were only resolved at startup time and never later during operation. The manual somewhat discouraged
their use, so probably this recommendation was copied.
Today’s version of ntpd can re-resolve DNS but only in a special configuration directive “pool”, not in the normal
“server” configuration. And “pool” is not present in the NTP server now. Probably MikroTik have to upgrade the
NTP server package and add some config items in their layer to allow “pool”.
Yes!
That is exactly what we need.
i think you’re right.