[pkg-ntp-maintainers] Bug#461461: Bug#461461: This bug is still present -- change to systemd did not fix it!

[Rick Thomas]

First of all, thanks very much for the prompt reply!

I’ll try it again in sid and stretch, but it was there the last time I looked.

The problem is not getting dhcpclient to give ntp servers.  I’ve put hard coded ipv4 addresses in /etc/default/ntpdate, so that’s not it.

The problem is that the network interface is not fully available when ntpdate runs.  I think this is because dhcpclient has not provided an IP address for the interface yet.

Here’s a snatch from journalctl that shows the problem in jessie:

> Aug 01 02:49:46 dillserver kernel: sungem_phy: PHY ID: 206053, addr: 0
> Aug 01 02:49:46 dillserver kernel: gem 0002:20:0f.0 eth0: Found BCM5401 PHY
> Aug 01 02:49:46 dillserver kernel: IPv6: ADDRCONF(NETDEV_UP): eth0: link is not ready
> Aug 01 02:49:46 dillserver ntpdate[661]: no servers can be used, exiting
> Aug 01 02:49:46 dillserver networking[469]: Configuring network interfaces...done.
> Aug 01 02:49:46 dillserver systemd[1]: Started LSB: Raise network interfaces..
> Aug 01 02:49:46 dillserver systemd[1]: Starting ifup for eth0...
> Aug 01 02:49:46 dillserver systemd[1]: Started ifup for eth0.
> Aug 01 02:49:46 dillserver systemd[1]: Starting Network.
> Aug 01 02:49:46 dillserver systemd[1]: Reached target Network.
> Aug 01 02:49:46 dillserver systemd[1]: Starting Network is Online.
> Aug 01 02:49:46 dillserver systemd[1]: Reached target Network is Online.
> Aug 01 02:49:46 dillserver systemd[1]: Starting LSB: RPC portmapper replacement...
> Aug 01 02:49:47 dillserver rpcbind[672]: Starting rpcbind daemon....
> Aug 01 02:49:47 dillserver systemd[1]: Started LSB: RPC portmapper replacement.
> Aug 01 02:49:47 dillserver systemd[1]: Starting RPC Port Mapper.
> Aug 01 02:49:47 dillserver systemd[1]: Reached target RPC Port Mapper.
> Aug 01 02:49:47 dillserver systemd[1]: Starting LSB: NFS support files common to client and server...
> Aug 01 02:49:47 dillserver dhclient[685]: Internet Systems Consortium DHCP Client 4.3.1
> Aug 01 02:49:47 dillserver dhclient[685]: Copyright 2004-2014 Internet Systems Consortium.
> Aug 01 02:49:47 dillserver dhclient[685]: All rights reserved.
> Aug 01 02:49:47 dillserver dhclient[685]: For info, please visit https://www.isc.org/software/dhcp/
> Aug 01 02:49:47 dillserver dhclient[685]: 
> Aug 01 02:49:47 dillserver ifup[671]: Internet Systems Consortium DHCP Client 4.3.1
> Aug 01 02:49:47 dillserver ifup[671]: Copyright 2004-2014 Internet Systems Consortium.
> Aug 01 02:49:47 dillserver ifup[671]: All rights reserved.
> Aug 01 02:49:47 dillserver ifup[671]: For info, please visit https://www.isc.org/software/dhcp/
> Aug 01 02:49:47 dillserver dhclient[685]: Listening on LPF/eth0/00:03:93:3d:bd:bc
> Aug 01 02:49:47 dillserver dhclient[685]: Sending on   LPF/eth0/00:03:93:3d:bd:bc
> Aug 01 02:49:47 dillserver dhclient[685]: Sending on   Socket/fallback
> Aug 01 02:49:47 dillserver dhclient[685]: DHCPDISCOVER on eth0 to 255.255.255.255 port 67 interval 4
> Aug 01 02:49:47 dillserver ifup[671]: Listening on LPF/eth0/00:03:93:3d:bd:bc
> Aug 01 02:49:47 dillserver ifup[671]: Sending on   LPF/eth0/00:03:93:3d:bd:bc
> Aug 01 02:49:47 dillserver ifup[671]: Sending on   Socket/fallback
> Aug 01 02:49:47 dillserver ifup[671]: DHCPDISCOVER on eth0 to 255.255.255.255 port 67 interval 4
> 




On Aug 1, 2016, at 2:56 AM, Kurt Roeckx <kurt at roeckx.be> wrote:

> On Mon, Aug 01, 2016 at 02:37:58AM -0700, Rick Thomas wrote:
>> This 8 year old bug is still present in jessie and stretch -- the change to systemd did not fix it!
>> 
>> Please, somebody pay attention!  This bug makes ntpd unreliable tending to useless on systems that get their network config from dhcp.
> 
> There are various things broken, but as far as I know in stretch
> things should just work.
> 
> You seem to say that this is related to getting the ntp servers
> from dhcp, but that's not making sense to me.  The dhcp server
> should give you IP addresses, so it can never be a problem with
> DNS, the peers should always be there.
> 
> 
> Kurt
>