We have 2 VLANs, each VLAN has a server that provides DHCP, DNS and NTP to its corresponding VLAN. These 3 servers take time from a local NTP server. Here is the configuration of NTP client and servers on each VLAN and the problem of each setup:

VLAN 1:

NTP Server (Scientific Linux 7.3)

```
restrict default kod nomodify notrap nopeer noquery
restrict -6 default kod nomodify notrap nopeer noquery
logfile /var/log/ntp.log
driftfile /var/lib/ntp/drift
includefile /etc/ntp/crypto/pw
keys /etc/ntp/keys
restrict 127.0.0.1
restrict xx.xx.xx.xx mask XX.XX.XX.XX nomodify notrap

```

NTP Client (Scientific Linux 7.3)

```
driftfile /var/lib/ntp/drift
restrict default kod nomodify notrap nopeer noquery
restrict -6 default kod nomodify notrap nopeer noquery
restrict 127.0.0.1
restrict -6 ::1
includefile /etc/ntp/crypto/pw
keys /etc/ntp/keys
server yy.yy.yy.yy   # added by /sbin/dhclient-script

```

This server is always drifting 3 hours forward despite the correct timezone.

VLAN 2:

NTP Server (Scientific Linux 6.4)

```
restrict default kod nomodify notrap nopeer noquery
restrict -6 default kod nomodify notrap nopeer noquery
logfile /var/log/ntp.log
server 127.1.1.0 # local clock
fudge  127.127.1.0
driftfile /var/lib/ntp/drift
restrict 127.0.0.1
restrict xx.xx.xx.xx mask XX.XX.XX.XX nomodify notrap

```

NTP Client (Scientific Linux 6.4)

```
driftfile /var/lib/ntp/drift
restrict default kod nomodify notrap nopeer noquery
restrict -6 default kod nomodify notrap nopeer noquery
restrict 127.0.0.1
restrict -6 ::1
includefile /etc/ntp/crypto/pw
keys /etc/ntp/keys
server yy.yy.yy.yy   # added by /sbin/dhclient-script

```

Here I could not change the time zone. It should be `EET` but it is always `EEST` despite the `/etc/localtime` link value.

I have made sure that:

1. No firewall rules (`iptables -F`)
2. `ntpd` daemon is running and enabled (`chckonfig on`)
3. CentOS 7.x uses another time service called `chronyd` which blocks `ntpd` from startup. So I disabled it (Lost the source for this :( ).

After setting up these services, we synchronized them with our local NTP once. Through the DHCP configuration on each server we have `option ntp-servers xx.xx.xx.xx;` so the NTP information is distributed withing DHCP. I tried adding the local NTP server's address to the server's `/etc/ntp.conf` but the problem is still there.

Note that all servers are virtualized through VMWare ESXi.