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linux_wiki:synchronize_time_using_other_ntp_peers [2016/10/08 17:33] billdozor [NTP: Time Server] |
linux_wiki:synchronize_time_using_other_ntp_peers [2019/05/25 23:50] (current) |
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Synchronizing time to a central time server and also keeping in sync with a peer server. | Synchronizing time to a central time server and also keeping in sync with a peer server. | ||
- | This type of setup would be a tier two NTP setup, allowing for redundancy if the central source of time is lost. The two peers could agree on a time and provide it locally to other servers. | + | This type of setup is a tier two NTP setup, allowing for redundancy if the central source of time is lost. The two peers then agree on a time and provide it locally to other servers. |
---- | ---- | ||
- | ====== NTP: Time Server ====== | + | ====== Lab Setup ====== |
+ | |||
+ | The following virtual machines will be used: | ||
+ | * ipa.example.com (192.168.1.152) -> Central Time Server | ||
+ | * server1.example.com (192.168.1.150) -> NTP Server1 syncs with central (also peers with server2) | ||
+ | * server2.example.com (192.168.1.151) -> NTP Server2 syncs with central (also peers with server1) | ||
+ | |||
+ | ---- | ||
+ | |||
+ | ====== NTP: Central | ||
Setting up the " | Setting up the " | ||
* Server: ipa.example.com (192.168.1.152) | * Server: ipa.example.com (192.168.1.152) | ||
+ | * This server should already have ntpd installed and working if FreeIPA has been setup. | ||
\\ | \\ | ||
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====== NTP: Client Peering ====== | ====== NTP: Client Peering ====== | ||
- | Setup a NTP client | + | Setup the NTP clients |
+ | |||
+ | * Servers | ||
+ | * server1.example.com (192.168.1.150) | ||
+ | * server2.example.com (192.168.1.151) | ||
\\ | \\ | ||
Install required package | Install required package | ||
<code bash> | <code bash> | ||
- | yum install | + | yum install |
</ | </ | ||
Line 37: | Line 51: | ||
Enable and start the service | Enable and start the service | ||
<code bash> | <code bash> | ||
- | systemctl enable | + | systemctl enable |
- | systemctl start ntpd | + | systemctl start chronyd |
</ | </ | ||
\\ | \\ | ||
- | Edit the NTP config file | + | Edit the config file |
<code bash> | <code bash> | ||
- | vim /etc/ntp.conf | + | vim /etc/chrony.conf |
- | # Comment out all server lines, add peer for the newly created NTP server | + | # Comment out all server lines, add a new one |
- | peer 192.168.1.200 | + | server |
+ | |||
+ | # On server1: Peer with server2 | ||
+ | peer 192.168.1.151 | ||
+ | |||
+ | # On server2: Peer with server1 | ||
+ | peer 192.168.1.150 | ||
+ | </ | ||
+ | |||
+ | \\ | ||
+ | Ensure that the firewall allows NTP in (on both server1 and server2) | ||
+ | <code bash> | ||
+ | firewall-cmd --permanent --add-service=ntp | ||
+ | firewall-cmd --reload | ||
</ | </ | ||
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Restart the service | Restart the service | ||
<code bash> | <code bash> | ||
- | systemctl restart | + | systemctl restart |
</ | </ | ||
\\ | \\ | ||
- | Open the firewall for ntp | + | Ensure NTP time sync is enabled |
<code bash> | <code bash> | ||
- | firewall-cmd --permanent --add-service=ntp | + | timedatectl set-ntp true |
- | firewall-cmd --reload | + | </ |
+ | |||
+ | \\ | ||
+ | Check status | ||
+ | <code bash> | ||
+ | chronyc sources | ||
</ | </ | ||
+ | * Note: It may take a few minutes for the servers to enter a synced state on the peers. | ||
---- | ---- | ||