Table of contents
What is Network Time Protocol (NTP)?
NTP stands for Network Time Protocol, which is responsible to sync time to a central location or server. NTP is designed to synchronize the clocks on computers and networks across the Internet or Local Area Networks (LANs), MANs & WANs.
So why would I configure my network devices to sync its time with NTP server? Well, all network administrators require monitoring of their network and keep track record of all events happening in their network with actual timestamp. So imagine if your network got hacked then you would not know what and when it happened?
What Port does NTP uses?
NTP servers work in TCP / IP framework and use User Datagram Protocol UDP port 123.
Which time server should I use?
A good example of a NTP server is NTP POOL DOT ORG. This is a cluster of NTP servers that many servers and network devices use to synchronize their clocks.
How do I know that NTP is Accurate?
NTP uses concept of Stratum which defines how many NTP hops a device is from an authoritative time server. If a network device like router, switch or firewall is configured with multiple NTP servers it would prefer NTP server with lowest stratum.
Configure NTP Cisco
Below is the Step-by-Step Procedure to configure NTP in Cisco, optionally you can configure authentication with your NTP server. If we are using URL based NTP server like pool.ntp.org we need to configure name-server to resolve the URL to IP address as follows:
NTP Verification Commands Cisco
We can verify NTP status and associations in Cisco by using below mentioned commands.
NTP Configuration JunOS
Below is the Step-by-Step Procedure to configure NTP in Juniper, optionally you can configure authentication with your NTP server.
- Specify the boot server:
- Specify the NTP server:
- Specify the key number, authentication type (MD5), and key for authentication:
NTP Verification Commands Juniper
We can verify NTP status and associations in juniper by using below mentioned commands.
|user@juniper>show ntp status|
user@juniper>show ntp associations
NTP Configuration Fortigate
In our Fortigate firewall we are using our internal interface as source interface for time synchronization with NTP Server 22.214.171.124 with synchronization time of 30 minutes by default.
|config system ntp|
set ntpsync enable
set type custom
set syncinterval 30
set server “126.96.36.199”
set source-ip [LAN-IP]
set server-mode enable
set interface “internal”
NTP Verification Commands Fortigate
We can verify the NTP status in Fortigate as follows
fortigate#diag sys ntp status
In this article we have learnt what NTP is, how to configure NTP for cisco, how to configure NTP for juniper & lastly how to configure NTP for Fortigate. I hope this has been informative for you, if you like our content kindly do like our Facebook page.