#Kerberos client linux install
#Kerberos client linux update
#Kerberos client linux full
#Kerberos client linux Offline

Use a command such as вЂcat varlog/messages | grep ntpвЂ™ for specific lines only dealing with NTP.Д®verything should be syncing now, so it is time to enable Kerberos. For extreme troubleshooting, see the log at вЂ/var/log/messagesвЂ™. For more information, use the command вЂntpq -c asвЂ™. If you issue the command вЂntpq -pвЂ™ you should see server1 with an asterisk next to it to show it is the NTP Server being used. You need to restart and enable the service to start every time the system boots with the commands:

#Kerberos client linux Offline

If Server1 is offline for any reason, then server2 will contact the NTP Server that was left in the list. Make sure to add вЂpreferвЂ™ at the end so that server1 is the preferred NTP Server. Move the line вЂ server 0. iburstвЂ™ down and insert a line for server1:

#Kerberos client linux install

Install the NTP Daemon as we did on Server1:Д®dit the file вЂ/etc/ntp.confвЂ™ and remove the following three lines: It must be able to contact the NTP Server by using itвЂ™s Domain Name or IP Address.

#Kerberos client linux update

For Server2, go ahead and update the Hosts file and add Server1. Perform the hostname change on Server2 as well. Change the hostnames to match what you are using on your network.

#Kerberos client linux full

If you run the command вЂhostnameвЂ™ the full FQDN should be shown. Other than setting the Hosts file, we need to actually change the hostname. For an NTP Server, we really need the other systems that will be querying for time sync. If not, you need to edit the вЂ/etc/hostsвЂ™ and add Server1 and Server2. If you went over the article вЂ LFCS вЂ“ Creating OpenLDAP Server on CentOS 7вЂ™ then you have already set up Server1 and server2 in the Hosts file. Sudo firewall-cmd -add-service=ntp -permanent The first will open the specific port, the second reloads the firewall daemon for the changes to take effect: Next, we need to open the firewall for the NTP Server. A list will be produced and the default time server is the one with the asterisk at the beginning. We can check the NTP Daemon to see what servers it is querying for time synchronization with the command вЂsudo ntpq -pвЂ™.

Perform the following two commands to make this happen: Now that the changes have been made, we need to restart the service and enable it to auto-start when the system starts. For Server2, these lines will be modified.

You can modify these, but the default should be fine. Just below the modified line, there is a list of four servers that will be contacted by the NTP Server. The line will allow systems on the local network to query the Time Server to sync clocks, but not alter the time on the NTP Server. Remove the comment hash mark and change the IP Address to match your network. Once the package is installed, the configuration file will need to be edited. On Server1, perform the following command: Having a backup can help if a server is taken down, even for routine maintenance. A backup time server can be set in the case that the вЂTime ServerвЂ™ should be down. One system will be set up as the вЂTime ServerвЂ™ and all other systems will sync to that server. In a real environment, all systems, even the clients, need to sync the time. If you are using your VirtualBox servers to use as testing, make sure you do this on all servers. For this reason, all systems need to use the Network Time Protocol (NTP).ДЇor this to work, each system needs NTP.

AS вЂ“ Authentication Server that actually performs the authenticationД«ecause the tickets are granted on a timed basis, all systems need to be synchronized to the same time.

Kerberos Database вЂ“ Stores all passwords and identification of all allowed users.

Kerberos is made up of three important parts: Once granted, the two systems вЂtrustвЂ™ each other. Kerberos Authentication is a security measure that adds a level of security between two network systems. The key thing to remember is that the вЂticketвЂ™ expires after a certain amount of time. Once a user has entered a correct password, then they are granted a вЂticketвЂ™ to allow connection again without a password. Kerberos is an authentication method that can assign a user a вЂticketвЂ™ after the first sign-on.