Network

Question 1

lists all available network interfaces on your system

Answer 1

ip link show

Question 2

view device and address info of device ens3

Answer 2

ip addr show ens3

Question 3

show statistics about a specific network dev performance

Answer 3

ip -s link show ens3

Question 4

tests connectivity to a machine

Answer 4

ping -c3 192.0.2.254

ping6 2001:db8:0:1::1

Question 5

find other IPv6 nodes on the local network

Answer 5

ping6 ff02::1%ens4

Question 6

show routing information

Answer 6

ip route

ip -6 route

Question 7

trace the network traffic path to reach a remote host

Answer 7

tracepath access.redhat.com

mtr access.redhat.com

Question 8

display socket statistics.

Answer 8

ss -ta
ss -plunt

Question 9

Locate the network interface name that is associated with the 52:54:00:00:fa:0a Ethernet address

Answer 9

ip link

Question 10

Display the current IP address and netmask for all interfaces

Answer 10

ip -br addr

Question 11

Display the statistics for the enX interface.

Answer 11

ip -s link show enX

Question 12

Display the listening TCP sockets on the local system

Answer 12

ss -lt

Question 13

displays the status of all network devices

Answer 13

nmcli dev status

Question 14

displays a list of all connections.

Answer 14

nmcli con show

Question 15

displays a list of all active connections.

Answer 15

nmcli con show --active

Question 16

adds an eno2 connection of the ethernet type for the eno2 network interface

Answer 16

nmcli con add 
con-name eno2 
type ethernet 
ifname eno2

Question 17

creates an eno3 connection of the ethernet type for the eno3 network interface with a static IPv4 network setting

Answer 17

nmcli con add 
con-name eno3 
type ethernet 
ifname eno3 
ipv4.method manual 
ipv4.addresses 192.168.0.5/24 
ipv4.gateway 192.168.0.254

Question 18

activates a network connection on the device that it is bound to

Answer 18

nmcli con up static-ens3

Question 19

disconnects the network device and brings down the connection

Answer 19

nmcli dev disconnect ens3

Question 20

list the current settings for a connection

Answer 20

nmcli con show static-ens3

Question 21

update the static-ens3 connection to set the 192.0.2.2/24 IPv4 address and the 192.0.2.254 default gateway. automatically enable the connection at system boot.

Answer 21

nmcli con mod static-ens3
ipv4.addresses 192.0.2.2/24 
ipv4.gateway 192.0.2.254
connection.autoconnect yes

Question 22

update the static-ens3 connection to set the 2001:db8:0:1::a00:1/64 IPv6 address and the 2001:db8:0:1::1 default gateway

Answer 22

nmcli con mod static-ens3 
ipv6.addresses 2001:db8:0:1::a00:1/64
ipv6.gateway 2001:db8:0:1::1

Question 23

adds the 2.2.2.2 DNS server to the static-ens3 connection

Answer 23

nmcli con mod static-ens3 +ipv4.dns 2.2.2.2

Question 24

loads all connection profiles

Answer 24

nmcli con reload

Question 25

loads only the eno2 connection profile

Answer 25

```nmcli con reload en02```

Question 26

deletes a connection from the system

Answer 26

nmcli con del static-ens3

Question 27

view your current permissions

Answer 27

nmcli gen permissions

Question 28

useful network manager commands

Answer 28

nmcli dev status nmcli dev disconnect nmcli con show nmcli con up nmcli con reload nmclicon edit nmcli con mod nmcli con add nmcli con del

Question 29

NetworkManager config file format

Answer 29

ini

Question 30

Connection properties

Answer 30

ip4.address1 ip4.method ip4.gateway ip4.dns ip4.dns-search ip4.ignore-auto-dns connection.autoconnect connection.id connection.interface-name connection.type connection.uuid 802-3-ethernet.mac-address

Question 31

What do you do after changing a connection config file?

Answer 31

```nmcli con reload``` ```nmcli con up static-ens3```

Question 32

Determine hostname

Answer 32

hostname

Question 33

Where is hostname stored

Answer 33

/etc/hostname

Question 34

Set hostname via cli

Answer 34

```hostnamectl hostname example.com```

Question 35

How does stub resolver go about converting names to ips?

Answer 35

determines where to look based on /etc/nsswitch.conf . By default it uses /etc/hosts

Question 36

Command to test hostname resolution

Answer 36

getent hosts hostname

Question 37

Explain the content of /etc/resolv.conf

Answer 37

nameserver: up to 3 nameservers search: suffixes to append to requests when querying just a hostname domain: hostname resolution in a local network

Question 38

Change dns with nmcli

Answer 38

```nmcli con mod ID ipv4.dns IP``` ```nmcli con down ID``` ```nmcli con up ID```

Question 39

adds or removes an individual dns entry

Answer 39

```nmcli con mod ID +ipv4.dns IP```

Question 40

test DNS server connectivity

Answer 40

```dig example.com``` ```host example.com```

Question 41

test DNS server connectivity specifically usin /etc/hosts

Answer 41

```getent hosts example.com```