Linux ifconfig command details how to use Linux ifconfig command

Ifconfig can set the status of the network device or display the current settings.

Syntax

Ifconfig [network device] [down up-allmulti-arp-promisc] [add <address>] [del <address>]

[<Hw <network device type>

[Mem_start <memory address>] [metric <quantity>] [mtu <byte>] [netmask <subnet mask>] [tunnel <address>]

[-Broadcast <address>] [-pointopoint <address>] [IP address]

Parameter description:

• Add <address> set the IPv6 IP address of the network device.
• Del <address> delete the IPv6 IP address of the network device.
• Down to disable the specified network device.
• <Hw <network device type>
• Io_addr <I/O address> sets the I/O address of the network device.
• Irq <IRQ address> sets the IRQ of the network device.
• Media <network media type> sets the media type of the network device.
• Mem_start <memory address> sets the starting address occupied by the network device in the main memory.
• Metric <quantity> specifies the number of data packets to be added when calculating the number of data packets to be transferred.
• Mtu <byte> sets the MTU of the network device.
• Netmask <subnet mask> sets the subnet mask of the network device.
• Tunnel <address> establishes the tunnel communication address between IPv4 and IPv6.
• Up to start the specified network device.
• -Broadcast <address> processes data packets sent to the specified address as broadcast data packets.
• -The pointopoint <address> is directly connected to the network device of the specified address. This mode has the confidentiality function.
• -Promisc: disable or start the promiscuous mode of the specified network device.
• [IP address] specifies the IP address of the network device.
• [Network device] specifies the name of the network device.

Instance

Display Network Device Information

# Ifconfig

Eth0 Link encap: Ethernet HWaddr 00: 50: 56: 0A: 0B: 0C

Inet addr: 192.168.0.3 Bcast: 192.168.0.255 Mask: 255.255.255.0

Inet6 addr: fe80 :: 250: 56ff: fe0a: b0c/64 Scope: Link

Up broadcast running multicast mtu: 1500 Metric: 1

RX packets: 172220 errors: 0 dropped: 0 overruns: 0 frame: 0

TX packets: 132379 errors: 0 dropped: 0 overruns: 0 carrier: 0

Collisions: 0 fig: 1000

RX bytes: 87101880 (83.0 MiB) TX bytes: 41576123 (39.6 MiB)

Interrupt: 185 Base address: 0x2024

Lo Link encap: Local Loopback

Inet addr: 127.0.0.1 Mask: 255.0.0.0

Inet6 addr: 1/128 Scope: Host

Up loopback running mtu: 16436 Metric: 1

RX packets: 2022 errors: 0 dropped: 0 overruns: 0 frame: 0

TX packets: 2022 errors: 0 dropped: 0 overruns: 0 carrier: 0

Collisions: 0 txqueuelen: 0

RX bytes: 2459063 (2.3 MiB) TX bytes: 2459063 (2.3 MiB)

Enable or disable a specified Nic

# Ifconfig eth0 down

# Ifconfig eth0 up

Configure and delete IPv6 addresses for NICs

# Ifconfig eth0 add 33ffe: 3240: 800: 1005: 2/64 // the IPv6 address of the NIC.

# Ifconfig eth0 del 33ffe: 3240: 800: 1005: 2/64 // delete an IPv6 address for the NIC

Use ifconfig to modify the MAC address

# Ifconfig eth0 down // disable the NIC

# Ifconfig eth0 hw ether 00: AA: BB: CC: DD: EE // modify the MAC address

# Ifconfig eth0 up // start the NIC

# Ifconfig eth1 hw ether 00: 1D: 1C: 1D: 1E // disable the NIC and modify the MAC address

# Ifconfig eth1 up // start the NIC

Configure IP addresses

# Ifconfig eth0 192.168.1.56

// Configure an IP address for the eth0 Nic

# Ifconfig eth0 192.168.1.56 netmask 255.255.255.0

// Configure an IP address for the eth0 Nic and add a sub mask

# Ifconfig eth0 192.168.1.56 netmask 255.255.255.0 broadcast 192.168.1.255

// Configure an IP address for the eth0 Nic with a sub-mask and a broadcast address.

Enable and disable ARP

# Ifconfig eth0 arp // enable

# Ifconfig eth0-arp // disable

Set the maximum transmission unit

# Ifconfig eth0 mtu1500

// Set the maximum data packet size that can pass to 1500 bytes.