Interface Configuration (ifconfig)

Interface configuration refers to the setup and management of network interfaces on a device such as a router, switch, or computer.

Display Network Interface

This command is used to display all network interfaces, including both active and inactive ones.

ifconfig -a

This command displays detailed information about a specific network interface.

ifconfig emp0s3

Assign an IP Address

Assign an IP address temporarily to the network interface.

ifconfig emp0s3 192.168.0.40

Manually assign an IP address and subnet mask to the network interface.

ifconfig emp0s3 192.168.0.41 netmask 255.255.255.0

Assign an IP address with a subnet mask in CIDR notation.

ifconfig emp0s3 192.168.0.42/20

Disable the network interface.

ifconfig emp0s3 down

Enable the network interface.

ifconfig emp0s3 up

Create and assign an IP address to a virtual (alias) network interface.

ifconfig emp0s3:1 192.168.0.42

Enable/Disable Network Interface

Enable a network interface.

ifup emp0s3

Disable a network interface, stopping all network communication.

ifdown emp0s3

View Network Information

Display detailed information about all network interfaces and their assigned IP addresses.

ip addr show

Assign a new IP address to the network interface.

ip addr add 192.168.0.40/24 dev emp0s3

Disable the network interface.

ip link set emp0s3 down

Enable the network interface.

ip link set emp0s3 up

Routing Table Management

Display and manipulate the routing table in Linux.

ip route

Manually add a new route to a specific network.

ip route add 192.168.0.64/24 via 192.168.1.1 dev emp0s3

Delete a specific route.

ip route del 192.168.0.0/24

Set the default gateway.

ip route add default via 192.168.1.1 dev emp0s3

Display routing table entries for a specific network interface.

ip route show dev emp0s3

Remove/flush all routes from the main routing table.

ip route flush table main

Ping Command

Test network connectivity between two devices.

ping 8.8.8.8

Send only 2 packets.

ping 8.8.8.8 -c 2

Send a 65,500-byte packet (default is 56 bytes).

ping 192.168.1.1 -s 65500

Send 4 large ICMP packets (65,500 bytes each) from a specific network interface.

ping -I emp0s3 192.168.1.1 -s 65500 -c 4

Send 2 large ICMP packets (65,500 bytes each) from a specific network interface.

ping 192.168.1.1 -c 2 -s 65500 -I emp0s3 -p 42

Ping with a 10-second interval, sending only 2 packets.

ping 192.168.1.1 -i 10 -c 2

Ping using IPv6.

ping -6 armourinfosec.com

Send a flood of ICMP echo request packets with the maximum packet size.

ping 192.168.1.1 -f -s 65500

Traceroute Command

Track the path that packets take to reach a destination.

Install traceroute

For RHEL/CentOS:

yum install traceroute

For Debian/Ubuntu:

apt install traceroute

Trace the path that network packets take.

traceroute 8.8.8.8

Trace the route packets take using TCP packets.

tcptraceroute 8.8.8.8

Tracepath Command

Tracepath is a network diagnostic tool similar to traceroute, but it does not require root privileges and automatically detects the Maximum Transmission Unit (MTU) along the route.

Install iputils and iputils-tracepath