{"id":5110,"date":"2018-06-25T16:53:49","date_gmt":"2018-06-25T12:53:49","guid":{"rendered":"https:\/\/www.howtoforge.com\/linux-ifconfig-command\/"},"modified":"2018-06-25T16:53:49","modified_gmt":"2018-06-25T12:53:49","slug":"linux-ifconfig-command-tutorial-for-beginners-7-examples","status":"publish","type":"post","link":"https:\/\/afaghhosting.net\/blog\/linux-ifconfig-command-tutorial-for-beginners-7-examples\/","title":{"rendered":"Linux ifconfig Command Tutorial for Beginners (7 Examples)"},"content":{"rendered":"

Network management work includes a lot of stuff, and precisely for this reason, there are several Linux command line utilities that help you with different kind of network-related tasks. In this tutorial, we will discuss one such utility dubbed ifconfig<\/strong>. But before we start with it, it’s worth mentioning that all examples discussed in this article have been tested on an Ubuntu 16.04 LTS machine.<\/p>\n

Linux ifconfig command<\/h2>\n

The ifconfig command gives you the ability to configure network interfaces. Of course, you can also fetch information related to network interfaces with this tool. Following is its syntax:<\/p>\n

ifconfig [-v] [-a] [-s] [interface]
ifconfig [-v] interface [aftype] options | address …<\/p>\n

And here’s how the tool’s man page explains it:<\/p>\n

 Ifconfig\u00a0 is\u00a0 used to configure the kernel-resident network interfaces.\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 It is used at boot time to set up interfaces as necessary.\u00a0 After that,\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 it\u00a0 is\u00a0 usually\u00a0 only\u00a0 needed\u00a0 when\u00a0 debugging or when system tuning is\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 needed.
\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 If no arguments are given, ifconfig displays the\u00a0 status\u00a0 of\u00a0 the\u00a0 cur?\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 rently\u00a0 active interfaces.\u00a0 If a single interface argument is given, it\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 displays the status of the given interface only; if a single\u00a0 -a\u00a0 argu?\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 ment\u00a0 is\u00a0 given,\u00a0 it\u00a0 displays the status of all interfaces, even those\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 that are down.\u00a0 Otherwise, it configures an interface.<\/p><\/pre>\n
Following are some Q&A-styled examples that should give you a good idea on how the ifconfig command works.<\/p>\n
Q1. How to use the ifconfig command?<\/h2>\n
Basic usage is fairly simple – just execute the ‘ifconfig’ command sans any options.<\/p>\n
ifconfig<\/p>\n
In output, you’ll see information related to all active interfaces. For example, in my case, the following output was produced.<\/p>\n
\"How<\/a><\/p>\n
Note that in case you want the command to display all interfaces (including those currently down), use the -a command line option.<\/p>\n
Q2. How to make ifconfig display compact output?<\/h2>\n
For a short list output, use the -s command line option.<\/p>\n
ifconfig -s<\/p>\n
Here’s a sample output:<\/p>\n
\"How<\/a><\/p>\n
Q3. How to make ifconfig display info about a\u00a0specific interface?<\/h2>\n
This you can do by\u00a0specifying the name of the interface as an argument to the ifconfig command.<\/p>\n
ifconfig [interface-name]<\/p>\n
For example:<\/p>\n
\"How<\/a><\/p>\n
Q4. How to disable or enable a network interface using ifconfig?<\/h2>\n
To do this, just specify the ‘down’ or ‘up’ flags. For example, to disable an interface dubbed eth0, use the ifconfig command in the following way:<\/p>\n
ifconfig eth0 down<\/p>\n
Similarly, to enable, use the following command:<\/p>\n
ifconfig eth0 up<\/p>\n
Q5. How to change a network MTU using ifconfig?<\/h2>\n
This you can do by using the ‘mtu’ flag along with the new mtu value.<\/p>\n
ifconfig [interface-name] mtu [mtu-value]<\/p>\n
For example:<\/p>\n
ifconfig eth0 mtu 900<\/p>\n
PS: For those who aren’t aware what MTU is, head here<\/a>.<\/p>\n
Q6. How to enable promiscuous mode on an interface?<\/h2>\n
Promiscuous mode allows a network to receive all packets on the network. If that’s your requirement, you can enable this mode using the ‘promisc’ flag.<\/p>\n
For example:<\/p>\n
ifconfig eth0 promisc<\/p>\n
Note that you can disable the promiscuous mode in the following way:<\/p>\n
ifconfig eth0 -promisc<\/p>\n
Q7. How to change hardware address of network interface?<\/h2>\n
The ifconfig command also allows you to change the MAC address corresponding to a network interface. This you can do in the following way:<\/p>\n
ifconfig [network-name] hw [class] [hardware-address]<\/p>\n
For example:<\/p>\n
ifconfig eth0 hw ether 70:4d:7b:70:d2:3e<\/p>\n
Here’s how the man page explains this option:<\/p>\n
 Set the hardware address of this interface, if the device driver\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 supports\u00a0 this\u00a0 operation.\u00a0 The keyword must be followed by the\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 name of the hardware class and the printable ASCII equivalent of\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 the\u00a0 hardware\u00a0 address.\u00a0\u00a0 Hardware\u00a0 classes\u00a0 currently supported\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 include ether (Ethernet), ax25 (AMPR AX.25), ARCnet\u00a0 and\u00a0 netrom\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 (AMPR NET\/ROM).<\/pre>\n
Conclusion<\/h2>\n
So you can see, the ifconfig command lets you do a lot of things related to network interfaces. While we have discussed quite a few command line options here, there are many others as well. Once you are done practicing the ones we’ve discussed here, head to the tool’s\u00a0man page<\/a> to learn more.<\/p>\n
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Network management work includes a lot of stuff, and precisely for this reason, there are several Linux command line utilities that help you with different kind of network-related tasks. In this tutorial, we will discuss one such utility dubbed ifconfig. But before we start with it, it’s worth mentioning that all examples discussed in this […]<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"closed","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[36],"tags":[],"class_list":["post-5110","post","type-post","status-publish","format-standard","hentry","category-36"],"_links":{"self":[{"href":"https:\/\/afaghhosting.net\/blog\/wp-json\/wp\/v2\/posts\/5110","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/afaghhosting.net\/blog\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/afaghhosting.net\/blog\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/afaghhosting.net\/blog\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/afaghhosting.net\/blog\/wp-json\/wp\/v2\/comments?post=5110"}],"version-history":[{"count":0,"href":"https:\/\/afaghhosting.net\/blog\/wp-json\/wp\/v2\/posts\/5110\/revisions"}],"wp:attachment":[{"href":"https:\/\/afaghhosting.net\/blog\/wp-json\/wp\/v2\/media?parent=5110"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/afaghhosting.net\/blog\/wp-json\/wp\/v2\/categories?post=5110"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/afaghhosting.net\/blog\/wp-json\/wp\/v2\/tags?post=5110"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}