I’m sure nobody is ever going to read this but I wondered why router manufacts always include name serving and always never include time serving. Seems odd to leave that at clients. In a LAN it would make an awefull lot of sense if all devices have a same sense of time and what better equipement is there than a router? It serves names, or relays them why shouldnt it server time?
This is why
I suspect it’s because it’s a lot more convenient for the operating system to point at several well-known NTP servers on the Internet, perhaps provided by the OS distributor, rather than try to guess whether the user’s default gateway will have an NTP server on it.
End user systems on the network tend to get their DNS resolver IP by DHCP, and that can work for their NTP server(s) as well, but it never really caught on and in any case, you need at least 3, so I’m not sure it’s a good idea to just have the consumer router send out DHCP with just its single IP listed as NTP provider.
What we have now seems better.
The routers/gateways as they serve DNS, they supposed to do the same with NTP. Unfortunately not all end device supports the NTP server config via DHCP, even if the information is already available.
Imagine a client with systemd-timesyncd. That is one of the lightest service among the different NTP client daemon implementations. It uses only one NTP server at a time, and that perfectly match the default number of NTP servers on the LAN, the default gateway. There is no need for extra security, assuming that the gateway uses one of the safest NTP server software, ntpd-rs or ntpsec with NTS enabled and with multiple NTP servers.
It would also solve the issue mentioned in another thread, the rate-limiting when a nasty workaround, the NAT is in place: end clients do not have to access a given NTP server competing for the same public IP address so adding up the number of NTP packets from the NTP server’s point of view.
In fact many of them do, believe it or not.
As they broadcast the time-server via DHCP into your local lan.
I have many routers here in the house and they all do.
Fritzbox, OpenWRT, DrayTek, Asus, MicroTek, etc.
I can’t remember any modern (less then 10 years old) that doesn’t do this.
Mint/Ubuntu does pickup on this DHCP info and appoints the router-ntp info, sadly it doesn’t always work well.
Other silly thing, why don’t ISP’s spread the time-protocol themselves to all connected clients via e.g. PPPoE? They do tell the DNS-servers but often (always?) fail to give time-servers.
I do agree with you, it should be default in routers and dhcp, sadly it’s not always the case.