Validate Network Configuration

Question 1

What will the command “ip link” do?

Answer 1

List all available network interfaces on your system.

Question 2

What will the command “ip addr show” do?

Answer 2

It will list all network interfaces and their assigned IP addresses.

Question 3

What option flag of the “ip link” command will show statistics about an interfaces network performance?

Answer 3

-s

Question 4

What option flag of the ping command will limit the number of packets sent?

Answer 4

-cN

N = the number of packets to send

Question 5

What command is the IPv6 version of ping?

Answer 5

ping6

Question 6

What CLI command will show the system’s routing information?

Answer 6

ip route or
ip -6 route for the IPv6 route

Question 7

What CLI command(s) would you use to troubleshoot a network traffic path?

Answer 7

traceroute or
tracepath

Question 8

What option flags are use with traceroute to specify the transport protocol?

Answer 8

-I ICMP
-T TCP
no flag (default) UDP

Question 9

What CLI command(s) would you use to troubleshoot an IPv6 network traffic path?

Answer 9

tracepath6 or
traceroute -6

Question 10

What CLI command(s) would you use to list all open TCP sockets on a sysytem?

Answer 10

ss -ta or
netstat -ta (legacy)

Options:
-a list all listening and established sockets
-t list TCP sockets
-u list UDP sockets
-p list process using socket

Question 11

What does the NetworkManager service do?

Answer 11

Monitor and manage a system’s network settings.

Question 12

In what directory does NetworkManager store network profiles?

Answer 12

/etc/NetworkManager/system-connections

Question 13

What CLI utility is used to create an edit network connection files (profiles)?

Answer 13

nmcli

Question 14

What CLI command will list all active network connections?

Answer 14

nmcli con show --active

Question 15

What CLI command would create a network ethernet connection named con-name for the eno2 interface?

Answer 15

nmcli con add con-name eno2 type ethernet ifname eno2

Question 16

What options to nmcli add con would make the connection IPv4 static at 192.168.0.15/24 with gateway 192.168.0.1?

Answer 16

ipv4.method manual ipv4.addresses 192.168.0.15/24 ipv4.gateway 192.168.0.1

Question 17

What CLI command would you use to disconnect a network device and bring down the connection?

Answer 17

nmcli dev disconnect <iface name>

Question 18

What CLI command will display or temporarily modify the system’s FQDN?

Answer 18

hostname

Question 19

What CLI utility will permanently change to hostname in the /etc/hostname file

Answer 19

hostnamectl hostname <new_hostname>

Question 20

In what file are name IP address to name definitions for name resolution stored?

Answer 20

/etc/hosts

Question 21

What CLI command(s) would you use to test DNS server connectivity?

Answer 21

host <hostname|IP> or
dig <hostname|IP>

Question 22

What CLI command would you use to test the /etc/hosts file for a hostname entry?

Answer 22

getent hosts [hostname|IP]