Hack The Sec-Leading Resource Of Linux Tutorial: NIC

<div dir="ltr" style="text-align: left;" trbidi="on">
<h1 class="post-title" style="background-color: white; border: 0px; font-family: 'PT Serif', serif; font-size: 38px; font-stretch: inherit; font-weight: 400; letter-spacing: -1px; line-height: 1.3em; margin: 0px 0px 10px; padding: 0px; vertical-align: baseline; word-wrap: break-word;">
<span style="color: #990000;"><u><i>Configure NIC(Network Interface Card) bonding in CentOS 7 / RHEL 7</i></u></span></h1>
<div>
<div style="background-color: white; border: 0px; font-family: 'PT Serif', serif; font-size: 16px; font-stretch: inherit; line-height: 22.4px; margin-bottom: 1em; padding: 0px; vertical-align: baseline;">
NIC(Network Interface Card) bonding is also known as Network bonding. It can be defined as the aggregation or combination of multiple NIC  into a single bond interface. It’s main purpose is to provide high availability and redundancy.</div>
<div style="background-color: white; border: 0px; font-family: 'PT Serif', serif; font-size: 16px; font-stretch: inherit; line-height: 22.4px; margin-bottom: 1em; padding: 0px; vertical-align: baseline;">
In this article we will learn how to configure nic or netwok bonding in <a href="http://www.hackthesec.co.in/search/label/Centos" target="_blank">CentOS </a>7 & <a href="http://www.hackthesec.co.in/search/label/Rhel7" target="_blank">RHEL 7</a>. In my case i have two interface cards (enp0s3 & enp0s8) and will form a bond interface (bond0).</div>
<div class="separator" style="clear: both; text-align: center;">
<a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEhlJ5P0qDfh0m0fvpo5xFpkQiS0W83L2gMP9c4SNwWQH0XOpkknpTXclyIaSeSZKson8JQzNfFvUq3tc21293NiEZ4OVaSyyzLtVVaKUfwCzdSOEdwvrd-pDVf7TWGIwwGeWQlilD4SOglT/s1600/nic_www.hackthesec.co.in.jpg" imageanchor="1" style="margin-left: 1em; margin-right: 1em;"><img border="0" height="203" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEhlJ5P0qDfh0m0fvpo5xFpkQiS0W83L2gMP9c4SNwWQH0XOpkknpTXclyIaSeSZKson8JQzNfFvUq3tc21293NiEZ4OVaSyyzLtVVaKUfwCzdSOEdwvrd-pDVf7TWGIwwGeWQlilD4SOglT/s320/nic_www.hackthesec.co.in.jpg" width="320" /></a></div>
<div style="background-color: white; border: 0px; font-family: 'PT Serif', serif; font-size: 16px; font-stretch: inherit; line-height: 22.4px; margin-bottom: 1em; padding: 0px; vertical-align: baseline;">
<br /></div>
<h2 style="background-color: white; border: 0px; color: #155c8e; font-family: 'PT Serif', serif; font-size: 34px; font-stretch: inherit; font-weight: 400; letter-spacing: -0.7px; line-height: 1.3em; margin: 0px 0px 14px; padding: 0px; vertical-align: baseline; word-wrap: break-word;">
Prerequisite :</h2>
<div style="background-color: white; border: 0px; font-family: 'PT Serif', serif; font-size: 16px; font-stretch: inherit; line-height: 22.4px; margin-bottom: 1em; padding: 0px; vertical-align: baseline;">
If bonding module is not loaded on your linux box then use the below command to load.</div>
<pre style="background: rgb(54, 54, 54); border-radius: 7px; border: 1px solid rgb(221, 221, 221); font-family: Monaco, 'Courier New', 'DejaVu Sans Mono', 'Bitstream Vera Sans Mono', monospace; font-size: 12px; font-stretch: inherit; line-height: 19px; margin-bottom: 15px; margin-top: 15px; overflow-x: auto; overflow-y: hidden; padding: 18px 20px; vertical-align: baseline; white-space: pre-wrap;"><span style="color: white;">[root@openstack ~]# </span><span style="color: lime;">modprobe </span><span style="color: white;">bonding</span></pre>
<div style="background-color: white; border: 0px; font-family: 'PT Serif', serif; font-size: 16px; font-stretch: inherit; line-height: 22.4px; margin-bottom: 1em; padding: 0px; vertical-align: baseline;">
To list the bonding module info, use following command.</div>
<pre style="background: rgb(54, 54, 54); border-radius: 7px; border: 1px solid rgb(221, 221, 221); color: white; font-family: Monaco, 'Courier New', 'DejaVu Sans Mono', 'Bitstream Vera Sans Mono', monospace; font-size: 12px; font-stretch: inherit; line-height: 19px; margin-bottom: 15px; margin-top: 15px; overflow-x: auto; overflow-y: hidden; padding: 18px 20px; vertical-align: baseline; white-space: pre-wrap;">[root@openstack ~]# modinfo bonding</pre>
<div style="background-color: white; border: 0px; font-family: 'PT Serif', serif; font-size: 16px; font-stretch: inherit; line-height: 22.4px; margin-bottom: 1em; padding: 0px; vertical-align: baseline;">
Output will be something like below</div>
<div class="separator" style="clear: both; text-align: center;">
<a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEhudrJtHvDHDO2QHkd6LkeTZW47lVuz2-Ooqhh4oXd3q-UG63Y-pMCS9naylHm6uBVzBE_TjGsW3IFCE8DLo9c5kdjhjN7XnDX2pv57oEMDuEqNFPJw5gLirekMUJL1dhebgpuqyt-BD7Ft/s1600/modinfo-bonding_www.hackthesec.co.in.jpg" imageanchor="1" style="margin-left: 1em; margin-right: 1em;"><img border="0" height="288" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEhudrJtHvDHDO2QHkd6LkeTZW47lVuz2-Ooqhh4oXd3q-UG63Y-pMCS9naylHm6uBVzBE_TjGsW3IFCE8DLo9c5kdjhjN7XnDX2pv57oEMDuEqNFPJw5gLirekMUJL1dhebgpuqyt-BD7Ft/s640/modinfo-bonding_www.hackthesec.co.in.jpg" width="640" /></a></div>
<div style="background-color: white; border: 0px; font-family: 'PT Serif', serif; font-size: 16px; font-stretch: inherit; line-height: 22.4px; margin-bottom: 1em; padding: 0px; vertical-align: baseline;">
<br /></div>
<h5 style="background-color: white; border: 0px; font-family: 'PT Serif', serif; font-size: 20px; font-stretch: inherit; line-height: 1.3em; margin: 0px 0px 14px; padding: 0px; vertical-align: baseline; word-wrap: break-word;">
<span style="border-image-outset: initial; border-image-repeat: initial; border-image-slice: initial; border-image-source: initial; border-image-width: initial; border: 0px; font-family: inherit; font-size: inherit; font-stretch: inherit; font-style: inherit; font-variant: inherit; font-weight: inherit; line-height: inherit; margin: 0px; padding: 0px; vertical-align: baseline;"><span style="color: #0b5394;">Step:1 Create Bond Interface File</span></span></h5>
<div style="background-color: white; border: 0px; font-family: 'PT Serif', serif; font-size: 16px; font-stretch: inherit; line-height: 22.4px; margin-bottom: 1em; padding: 0px; vertical-align: baseline;">
Create a bond interface file (<span style="border: 0px; font-family: inherit; font-size: inherit; font-stretch: inherit; font-style: inherit; font-variant: inherit; font-weight: 600; line-height: inherit; margin: 0px; padding: 0px; vertical-align: baseline;"><span style="color: red;">ifcfg-bond0</span></span>) under the folder “<span style="border: 0px; font-family: inherit; font-size: inherit; font-stretch: inherit; font-style: inherit; font-variant: inherit; font-weight: 600; line-height: inherit; margin: 0px; padding: 0px; vertical-align: baseline;"><span style="color: red;">/etc/sysconfig/network-scripts/</span></span>”</div>
<pre style="background: rgb(54, 54, 54); border-radius: 7px; border: 1px solid rgb(221, 221, 221); font-family: Monaco, 'Courier New', 'DejaVu Sans Mono', 'Bitstream Vera Sans Mono', monospace; font-size: 12px; font-stretch: inherit; line-height: 19px; margin-bottom: 15px; margin-top: 15px; overflow-x: auto; overflow-y: hidden; padding: 18px 20px; vertical-align: baseline; white-space: pre-wrap;"><span style="color: white;">[root@openstack network-scripts]# vi </span><span style="color: lime;">ifcfg-bond0</span><span style="color: white;">
</span><span style="color: lime;">DEVICE=bond0
</span><span style="color: white;">TYPE=Bond
NAME=bond0
BONDING_MASTER=yes
</span><span style="color: lime;">BOOTPROTO=none
</span><span style="color: white;">ONBOOT=yes
IPADDR=192.168.1.70
NETMASK=255.255.255.0
GATEWAY=192.168.1.1
BONDING_OPTS="mode=5 miimon=100"</span></pre>
<div style="background-color: white; border: 0px; font-family: 'PT Serif', serif; font-size: 16px; font-stretch: inherit; line-height: 22.4px; margin-bottom: 1em; padding: 0px; vertical-align: baseline;">
Save & exit the file.</div>
<div style="background-color: white; border: 0px; font-family: 'PT Serif', serif; font-size: 16px; font-stretch: inherit; line-height: 22.4px; margin-bottom: 1em; padding: 0px; vertical-align: baseline;">
Specify the IP address, Netmask & bonding modes as per your requirement. In my example i am using ‘<span style="border: 0px; font-family: inherit; font-size: inherit; font-stretch: inherit; font-style: inherit; font-variant: inherit; font-weight: 600; line-height: inherit; margin: 0px; padding: 0px; vertical-align: baseline;"><span style="color: red;">mode=5</span>′</span> which is used to provide fault tolerance and load balancing.</div>
<br /><h5 style="background-color: white; border: 0px; font-family: 'PT Serif', serif; font-size: 20px; font-stretch: inherit; line-height: 1.3em; margin: 0px 0px 14px; padding: 0px; vertical-align: baseline; word-wrap: break-word;">
<span style="border-image-outset: initial; border-image-repeat: initial; border-image-slice: initial; border-image-source: initial; border-image-width: initial; border: 0px; font-family: inherit; font-size: inherit; font-stretch: inherit; font-style: inherit; font-variant: inherit; font-weight: inherit; line-height: inherit; margin: 0px; padding: 0px; vertical-align: baseline;"><span style="color: red;">Step:2 Edit the NIC interface files</span></span></h5>
<div style="background-color: white; border: 0px; font-family: 'PT Serif', serif; font-size: 16px; font-stretch: inherit; line-height: 22.4px; margin-bottom: 1em; padding: 0px; vertical-align: baseline;">
<span style="border: 0px; font-family: inherit; font-size: inherit; font-stretch: inherit; font-style: inherit; font-variant: inherit; font-weight: 600; line-height: inherit; margin: 0px; padding: 0px; vertical-align: baseline;"><span style="color: red;">For ifcfg-enp0s3</span></span></div>
<pre style="background: rgb(54, 54, 54); border-radius: 7px; border: 1px solid rgb(221, 221, 221); font-family: Monaco, 'Courier New', 'DejaVu Sans Mono', 'Bitstream Vera Sans Mono', monospace; font-size: 12px; font-stretch: inherit; line-height: 19px; margin-bottom: 15px; margin-top: 15px; overflow-x: auto; overflow-y: hidden; padding: 18px 20px; vertical-align: baseline; white-space: pre-wrap;"><span style="color: white;">[root@openstack ~]# vi /etc/</span><span style="color: lime;">sysconfig/network-scripts/ifcfg-enp0s3</span><span style="color: white;">
TYPE=Ethernet
BOOTPROTO=none
DEVICE=enp0s3
ONBOOT=yes
</span><span style="color: lime;">HWADDR="08:00:27:69:60:c9"
</span><span style="color: white;">MASTER=bond0
SLAVE=yes</span></pre>
<div style="background-color: white; border: 0px; font-family: 'PT Serif', serif; font-size: 16px; font-stretch: inherit; line-height: 22.4px; margin-bottom: 1em; padding: 0px; vertical-align: baseline;">
<span style="border: 0px; font-family: inherit; font-size: inherit; font-stretch: inherit; font-style: inherit; font-variant: inherit; font-weight: 600; line-height: inherit; margin: 0px; padding: 0px; vertical-align: baseline;"><span style="color: red;">For ifcfg-enp0s8</span></span></div>
<pre style="background: rgb(54, 54, 54); border-radius: 7px; border: 1px solid rgb(221, 221, 221); font-family: Monaco, 'Courier New', 'DejaVu Sans Mono', 'Bitstream Vera Sans Mono', monospace; font-size: 12px; font-stretch: inherit; line-height: 19px; margin-bottom: 15px; margin-top: 15px; overflow-x: auto; overflow-y: hidden; padding: 18px 20px; vertical-align: baseline; white-space: pre-wrap;"><span style="color: white;">[root@openstack ~]# cat /etc/</span><span style="color: lime;">sysconfig/network-scripts/ifcfg-enp0s8</span><span style="color: white;">
TYPE=Ethernet
BOOTPROTO=none
</span><span style="color: lime;">DEVICE=enp0s8
</span><span style="color: white;">ONBOOT=yes
</span><span style="color: lime;">HWADDR="08:00:27:ea:71:8d"
</span><span style="color: white;">MASTER=bond0
SLAVE=yes</span></pre>
<h5 style="background-color: white; border: 0px; font-family: 'PT Serif', serif; font-size: 20px; font-stretch: inherit; line-height: 1.3em; margin: 0px 0px 14px; padding: 0px; vertical-align: baseline; word-wrap: break-word;">
<span style="border-image-outset: initial; border-image-repeat: initial; border-image-slice: initial; border-image-source: initial; border-image-width: initial; border: 0px; font-family: inherit; font-size: inherit; font-stretch: inherit; font-style: inherit; font-variant: inherit; font-weight: inherit; line-height: inherit; margin: 0px; padding: 0px; vertical-align: baseline;"><span style="color: #0b5394;">Step:3 Restart the Network Service</span></span></h5>
<div style="background-color: white; border: 0px; font-family: 'PT Serif', serif; font-size: 16px; font-stretch: inherit; line-height: 22.4px; margin-bottom: 1em; padding: 0px; vertical-align: baseline;">
Below command will restart the network service and will bring above changes into the effect.</div>
<pre style="background: rgb(54, 54, 54); border-radius: 7px; border: 1px solid rgb(221, 221, 221); font-family: Monaco, 'Courier New', 'DejaVu Sans Mono', 'Bitstream Vera Sans Mono', monospace; font-size: 12px; font-stretch: inherit; line-height: 19px; margin-bottom: 15px; margin-top: 15px; overflow-x: auto; overflow-y: hidden; padding: 18px 20px; vertical-align: baseline; white-space: pre-wrap;"><span style="color: white;">[root@openstack ~]# </span><span style="color: lime;">systemctl restart network.service</span></pre>
<h5 style="background-color: white; border: 0px; font-family: 'PT Serif', serif; font-size: 20px; font-stretch: inherit; line-height: 1.3em; margin: 0px 0px 14px; padding: 0px; vertical-align: baseline; word-wrap: break-word;">
<span style="border-image-outset: initial; border-image-repeat: initial; border-image-slice: initial; border-image-source: initial; border-image-width: initial; border: 0px; font-family: inherit; font-size: inherit; font-stretch: inherit; font-style: inherit; font-variant: inherit; font-weight: inherit; line-height: inherit; margin: 0px; padding: 0px; vertical-align: baseline;"><span style="color: #0b5394;">Step:4 Test & Verify bond interface.</span></span></h5>
<div style="background-color: white; border: 0px; font-family: 'PT Serif', serif; font-size: 16px; font-stretch: inherit; line-height: 22.4px; margin-bottom: 1em; padding: 0px; vertical-align: baseline;">
Use ‘<span style="border: 0px; font-family: inherit; font-size: inherit; font-stretch: inherit; font-style: inherit; font-variant: inherit; font-weight: 600; line-height: inherit; margin: 0px; padding: 0px; vertical-align: baseline;"><span style="color: red;">ifconfig</span></span>‘ & ‘<span style="border: 0px; font-family: inherit; font-size: inherit; font-stretch: inherit; font-style: inherit; font-variant: inherit; font-weight: 600; line-height: inherit; margin: 0px; padding: 0px; vertical-align: baseline;"><span style="color: red;">ip add</span></span>‘ command to check bond interface along with its slave interfaces.</div>
<div class="separator" style="clear: both; text-align: center;">
<a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEgQJ4uIl7RYeUcTQrlLtYbabZ53Onz5luI9iBtNB8vvPSkvZd7glCQ2Is_rhUsQIaMcbgnN58g8ipA6PP4A29SXY2qmOG-5krQnw52pFXlsUUtC8picTK9X8426REHtQJLlYmGWeAesemGf/s1600/ifconfig-bond_www.hackthesec.co.in.jpg" imageanchor="1" style="margin-left: 1em; margin-right: 1em;"><img border="0" height="350" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEgQJ4uIl7RYeUcTQrlLtYbabZ53Onz5luI9iBtNB8vvPSkvZd7glCQ2Is_rhUsQIaMcbgnN58g8ipA6PP4A29SXY2qmOG-5krQnw52pFXlsUUtC8picTK9X8426REHtQJLlYmGWeAesemGf/s640/ifconfig-bond_www.hackthesec.co.in.jpg" width="640" /></a></div>
<div style="background-color: white; border: 0px; font-family: 'PT Serif', serif; font-size: 16px; font-stretch: inherit; line-height: 22.4px; margin-bottom: 1em; padding: 0px; vertical-align: baseline;">
<br /></div>
<div style="background-color: white; border: 0px; font-family: 'PT Serif', serif; font-size: 16px; font-stretch: inherit; line-height: 22.4px; margin-bottom: 1em; padding: 0px; vertical-align: baseline;">
Use following command to view bond interface settings like bonding mode & slave interface.</div>
<pre style="background: rgb(54, 54, 54); border-radius: 7px; border: 1px solid rgb(221, 221, 221); font-family: Monaco, 'Courier New', 'DejaVu Sans Mono', 'Bitstream Vera Sans Mono', monospace; font-size: 12px; font-stretch: inherit; line-height: 19px; margin-bottom: 15px; margin-top: 15px; overflow-x: auto; overflow-y: hidden; padding: 18px 20px; vertical-align: baseline; white-space: pre-wrap;"><span style="color: white;">[root@openstack ~]# cat /proc/net/</span><span style="color: lime;">bonding/bond0</span></pre>
<div class="separator" style="clear: both; text-align: center;">
<a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEifLSZ5SMb-6KrNUIqvoMAqzni7GHeXc5WXmc7E92jzLzjKikUzXDen46Q4nlyoc5lKCyGjhoWoMBr9H6PKTF47C-s54sK3zgCdXFPFvMw2F2wGlHecsEkZdiQ3y3Oc0fA3vsWokNtBqJ7K/s1600/bonding-settings_www.hackthesec.co.in.jpg" imageanchor="1" style="margin-left: 1em; margin-right: 1em;"><img border="0" height="394" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEifLSZ5SMb-6KrNUIqvoMAqzni7GHeXc5WXmc7E92jzLzjKikUzXDen46Q4nlyoc5lKCyGjhoWoMBr9H6PKTF47C-s54sK3zgCdXFPFvMw2F2wGlHecsEkZdiQ3y3Oc0fA3vsWokNtBqJ7K/s640/bonding-settings_www.hackthesec.co.in.jpg" width="640" /></a></div>
<div style="background-color: white; border: 0px; font-family: 'PT Serif', serif; font-size: 16px; font-stretch: inherit; line-height: 22.4px; margin-bottom: 1em; padding: 0px; vertical-align: baseline;">
<br /></div>
<h5 style="background-color: white; border: 0px; font-family: 'PT Serif', serif; font-size: 20px; font-stretch: inherit; line-height: 1.3em; margin: 0px 0px 14px; padding: 0px; vertical-align: baseline; word-wrap: break-word;">
<span style="border-image-outset: initial; border-image-repeat: initial; border-image-slice: initial; border-image-source: initial; border-image-width: initial; border: 0px; font-family: inherit; font-size: inherit; font-stretch: inherit; font-style: inherit; font-variant: inherit; font-weight: inherit; line-height: inherit; margin: 0px; padding: 0px; vertical-align: baseline;"><span style="color: #0b5394;">Step:5 Fault tolerance testing</span></span></h5>
<div style="background-color: white; border: 0px; font-family: 'PT Serif', serif; font-size: 16px; font-stretch: inherit; line-height: 22.4px; margin-bottom: 1em; padding: 0px; vertical-align: baseline;">
To test the fault tolerance we can down one interface and check whether you are still able access the server.</div>
<pre style="background: rgb(54, 54, 54); border-radius: 7px; border: 1px solid rgb(221, 221, 221); font-family: Monaco, 'Courier New', 'DejaVu Sans Mono', 'Bitstream Vera Sans Mono', monospace; font-size: 12px; font-stretch: inherit; line-height: 19px; margin-bottom: 15px; margin-top: 15px; overflow-x: auto; overflow-y: hidden; padding: 18px 20px; vertical-align: baseline; white-space: pre-wrap;"><span style="color: white;">[root@openstack ~]# ifdown </span><span style="color: lime;">enp0s8</span><span style="color: white;">
Device 'enp0s8' successfully disconnected.
[root@openstack ~]#</span></pre>
<div class="separator" style="clear: both; text-align: center;">
<a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEhBWUdG-Ter-R-PywoumnQQe1jViI_iQKmdOlziNBHsT9XGN2_iS7bWzqBufwHfhRr0gbCpG9cH8QIMiypVSkG6hkNmaZl6AZNk4kK1bmtvgJJIgXQ_211pwDpqEgFUqgLKIl4mh6mS8hnf/s1600/fault-tolerance-bonding_www.hackthesec.co.in.jpg" imageanchor="1" style="margin-left: 1em; margin-right: 1em;"><img border="0" height="410" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEhBWUdG-Ter-R-PywoumnQQe1jViI_iQKmdOlziNBHsT9XGN2_iS7bWzqBufwHfhRr0gbCpG9cH8QIMiypVSkG6hkNmaZl6AZNk4kK1bmtvgJJIgXQ_211pwDpqEgFUqgLKIl4mh6mS8hnf/s640/fault-tolerance-bonding_www.hackthesec.co.in.jpg" width="640" /></a></div>
<div style="background-color: white; border: 0px; font-family: 'PT Serif', serif; font-size: 16px; font-stretch: inherit; line-height: 22.4px; margin-bottom: 1em; padding: 0px; vertical-align: baseline;">
<br /></div>
<div style="background-color: white; border: 0px; font-family: 'PT Serif', serif; font-size: 16px; font-stretch: inherit; line-height: 22.4px; margin-bottom: 1em; padding: 0px; vertical-align: baseline;">
<a href="http://www.hackthesec.co.in/" target="_blank">www.hackthesec.co.in</a><br /><a href="http://www.twitter.com/hackthesecurity">www.twitter.com/hackthesecurity</a></div>
</div>
</div>