SSH

• ps -ef | grep sshd → check ssh
• systemctl status sshd

DNS

• PTR record → IP to hostname

• A record → hostname to IP

• CNAME record → hostname to hostname

• /etc/named.conf → conf of DNS

• /var/named/ → file for DNS record

• systemctl restart named

• touch forward.lab reverse.lab

• dig client a in a 192.168.0.240

• systemctl start named

• systemctl enable named

Configuring permission

• chgrp named -R /var/named
• chown -v root:named /etc/named.conf
• restorecon -rv /var/named
• restorecon /etc/named.conf

Test DNS conf

• named-checkconf /etc/named.conf
• named-checkzone lab.local /var/named/forward.lab
• named-checkzone reverse.lab /var/named/reverse.lab

Add DNS info in network file

• nano /etc/sysconfig/network-scripts/ifcfg-enp0s3

• DNS=192.168.0.201

• systemctl restart NetworkManager

• nano /etc/resolv.conf

• nameserver 192.168.0.201

Test DNS server

• dig masterdns.lab.local
• nslookup masterdns.lab.local

Website lookup

• nslookup mywebsite.com

  • get IP of a website

• dig mywebsite.com

  • more info about website