Toolbox Aid

August 9th, 2024 12:23 PM Mr. Q Categories: Command

Command: ifconfig

Used to display or configure network interface parameters. It provides details about network interfaces, including IP addresses, MAC addresses, and network statistics.

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Sample Command and Output:

$ ifconfig
eth0: flags=4163<UP,BROADCAST,RUNNING,MULTICAST>  mtu 1500
        inet 192.168.1.10  netmask 255.255.255.0  broadcast 192.168.1.255
        inet6 fe80::a00:27ff:fe0a:8c0a  prefixlen 64  scopeid 0x20<link>
        ether 08:00:27:0a:8c:0a  txqueuelen 1000  (Ethernet)
        RX packets 1234  bytes 567890 (567.8 KB)
        TX packets 567  bytes 123456 (123.5 KB)
        interrupt 20

lo: flags=73<UP,LOOPBACK,RUNNING>  mtu 65536
        inet 127.0.0.1  netmask 255.0.0.0
        inet6 ::1  prefixlen 128  scopeid 0x10<host>
        loop  txqueuelen 1000  (Local Loopback)
        RX packets 123  bytes 4567 (4.5 KB)
        TX packets 123  bytes 4567 (4.5 KB)

Description:

• ifconfig: Displays information about all active network interfaces. The output includes:
• Interface Name: (e.g., eth0, lo)
• Flags: Indicates the status and capabilities of the interface (e.g., UP, BROADCAST).
• IP Address: The assigned IP address (e.g., 192.168.1.10).
• Netmask: Subnet mask (e.g., 255.255.255.0).
• MAC Address: Physical address (e.g., 08:00:27:0a:8c:0a).
• RX/TX Packets: Number of received and transmitted packets.
• Interrupt: IRQ number used by the interface.

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Additional Usage Examples:

• ifconfig eth0: Display information only for the eth0 interface. Sample Command and Output:

  $ ifconfig eth0
  eth0: flags=4163<UP,BROADCAST,RUNNING,MULTICAST>  mtu 1500
          inet 192.168.1.10  netmask 255.255.255.0  broadcast 192.168.1.255
          inet6 fe80::a00:27ff:fe0a:8c0a  prefixlen 64  scopeid 0x20<link>
          ether 08:00:27:0a:8c:0a  txqueuelen 1000  (Ethernet)
          RX packets 1234  bytes 567890 (567.8 KB)
          TX packets 567  bytes 123456 (123.5 KB)
          interrupt 20

• ifconfig -a: Display information about all interfaces, including inactive ones. Sample Command and Output:

  $ ifconfig -a
  eth0: flags=4163<UP,BROADCAST,RUNNING,MULTICAST>  mtu 1500
          inet 192.168.1.10  netmask 255.255.255.0  broadcast 192.168.1.255
          ...
  lo: flags=73<UP,LOOPBACK,RUNNING>  mtu 65536
          inet 127.0.0.1  netmask 255.0.0.0
          ...

Note: ifconfig is deprecated on some Linux distributions in favor of ip command. Use ip addr for similar functionality:

Command: ip addr

Sample Command and Output:

$ ip addr

Description:

• ip addr: Provides detailed information about network interfaces, including IP addresses and additional details.