1649
Comment:
|
1693
|
Deletions are marked like this. | Additions are marked like this. |
Line 29: | Line 29: |
NTP01 | `/var/log/syslog` on NTP01 |
Line 33: | Line 33: |
NTP02 | `/var/log/syslog` on NTP02 |
NTP
Keeping time is important. Especially when debugging an issue between servers. It is a pain comparing logfiles with a time skew. For that reason we will configure two NTP servers that all clients will synchronize their time to.
Configuring a redundant NTP server does not really make any sense. The DHCP server sends option ntp-servers to the DHCP clients, so if one NTP server is down, then the other will get the request instead.
Network
The NTP servers will have fixed IP-addresses. That is configured in the DHCP servers list of statically assigned IP-adresses by using the Domains MAC address.
- 192.168.1.40 ntp01
- 192.168.1.41 ntp02
Software
Set the Time
apt-get install ntpdate ntpdate pool.ntp.org hwclock --systohc
Install the NTP Daemon
apt-get install ntp
Debugging
/var/log/syslog on NTP01
Jan 30 06:39:30 ntp01 ntpd[464]: receive: KoD packet from 192.168.1.41 has inconsistent xmt/org/rec timestamps. Ignoring.
/var/log/syslog on NTP02
Jan 30 07:04:15 ntp02 ntpd[511]: receive: KoD packet from 192.168.1.40 has inconsistent xmt/org/rec timestamps. Ignoring.
While getting its IP-address via DHCP, the system will also ask the DHCP-server for any available NTP-servers. This causes the NTP server to synchronize time against itself, which again causes it to loose track of time. The solution is to tell its DHCP-client to not request the NTP information from the DHCP-server.
Make the following changes in /etc/dhcp/dhclient.conf
#rfc3442-classless-static-routes, ntp-servers; rfc3442-classless-static-routes;