Network Troubleshooting interview questions

The following are network troubleshooting interview questions and answers.

1. Name three steps which you would use to troubleshoot FTP server related problems?

Test basic connectivity with ping, Check with nmap if the ports are open (20 and 21). Check if a firewall is restricting traffic to the server.

2. How would you troubleshoot DNS problems?

Ping the DNS server and check the response. Check with wireshark if DNS request and response packets are being sent and received.

3. Name three steps which you would use to troubleshoot internet related problems?

Check the connectivity with the default gateway. Check if the DNS server is configured on the PC. Check if the appropriate port number is active using nmap on the DNS server.

4. How would you troubleshoot DHCP server related issues?

Check the IP connectivity with the DHCP server from a system configured on the network. Test if the DHCP client and server service is started on the DHCP server and the client. Test if the DHCP server service is reachable using nmap.

5. A user is unable to telnet into the router. Explain the methodology of troubleshooting?

Check the IP connectivity using ping. Check if port 23 is open on the router using nmap.

6. A user is able to ping IP addresses on the internet, but unable to access it via domain names. Should the DNS server be configured on the gateway or the client?

The DNS server can be a public server or the gateway address. If it is the gateway address, the DNS server address should be configured on the gateway. The DNS server should also be configured on the users TCP/IP adapter.