updated notes

src/rhcsa.md

@@ -779,3 +779,55 @@ sudo less /etc/services # Display the services
 ```
 
 ## Manage DNS and Logging
+
+### resolv.conf
+```bash
+sudo nano /etc/resolv.conf # Edit the resolv.conf file
+
+sudo systemctl restart NetworkManager # Restart the NetworkManager service
+```
+
+### nsswitch.conf
+```bash
+sudo nano /etc/nsswitch.conf # Edit the nsswitch.conf file
+
+sudo systemctl restart NetworkManager # Restart the NetworkManager service
+```
+
+### query dns
+```bash
+dig www.google.com # Query the DNS server for www.google.com
+
+dig -x 192.168.1.1 # Query the DNS server for the reverse lookup(PTR) of 192.168.1.1
+
+nslookup www.google.com # Query the DNS server for www.google.com
+
+nslookup -type=mx gmail.com # Query the DNS server for the MX records for gmail.com
+```
+
+### logging
+```bash
+sudo journalctl # Display the journal
+sudo journalctl -xe # Display the journal and show the boot messages
+sudo journalctl -f # Display the journal and follow the log
+
+sudo journalctl -u httpd # Display the journal for the httpd service
+
+sudo journalctl --since "1 hour ago" # Display the journal for the last hour
+sudo journalctl --since "1 hour ago" --until "2 hour ago" # Display the journal for the last hour and until 2 hours ago
+```
+
+### rsyslog
+```bash
+sudo nano /etc/rsyslog.conf # Edit the rsyslog configuration file
+
+sudo systemctl restart rsyslog # Restart the rsyslog service
+
+sudo systemctl status rsyslog # Display the status of the rsyslog service
+```
+
+### logrotate
+```bash
+sudo nano /etc/logrotate.conf # Edit the logrotate configuration file\
+```
+