How to bind multiple IP addresses to a network card in CentOS system
Today, I will talk to you about how to bind multiple IP addresses to a network card in the CentOS system. Many people may not know much about it. In order to make you understand better, the editor has summarized the following content for you. I hope you can get something according to this article.
First, let's find the IP address of the network card. In my CentOS 7 server, I only use one network card.
Run the following command with root privileges:
The code is as follows:
Ip addr
Sample output:
The code is as follows:
1: lo: mtu 65536 qdisc noqueue state UNKNOWN
Link/loopback 00:00:00:00:00:00 brd 00:00:00:00:00:00
Inet 127.0.0.1/8 scope host lo
Valid_lft forever preferred_lft forever
Inet6:: 1/128 scope host
Valid_lft forever preferred_lft forever
2: enp0s3: mtu 1500 qdisc pfifo_fast state UP qlen 1000
Link/ether 08:00:27:80:63:19 brd ff:ff:ff:ff:ff:ff
Inet 192.168.1.150/24 brd 192.168.1.255 scope global enp0s3
Valid_lft forever preferred_lft forever
As seen above, my network card name is enp0s3,ip and the address is 192.168.1.150.
As you know, the configuration file for the network card is stored in the / etc/sysconfig/network-scripts/ directory. The details of each network card will be stored under a different name, such as ifcfg-enp0s3.
Let's take a look at the details of ifcfg-enp0s3.
The code is as follows:
Cat / etc/sysconfig/network-scripts/ifcfg-enp0s3
Sample output:
The code is as follows:
TYPE= "Ethernet"
BOOTPROTO= "none"
DEFROUTE= "yes"
IPV4_FAILURE_FATAL= "no"
IPV6INIT= "yes"
IPV6_AUTOCONF= "yes"
IPV6_DEFROUTE= "yes"
IPV6_FAILURE_FATAL= "no"
NAME= "enp0s3"
UUID= "e9f9caef-cb9e-4a19-aace-767c6ee6f849"
ONBOOT= "yes"
HWADDR= "08VOG 00VOUR 27RU 80VOUR 63VOR 19"
IPADDR0= "192.168.1.150"
PREFIX0= "24"
GATEWAY0= "192.168.1.1"
DNS1= "192.168.1.1"
IPV6_PEERDNS= "yes"
IPV6_PEERROUTES= "yes"
OK, now we will assign multiple addresses in the same subnet.
Edit a file
The code is as follows:
/ etc/sysconfig/network-scripts/ifcfg-enp0s3:
Vi / etc/sysconfig/network-scripts/ifcfg-enp0s3
Add an additional IP address as below.
The code is as follows:
TYPE= "Ethernet"
BOOTPROTO= "none"
DEFROUTE= "yes"
IPV4_FAILURE_FATAL= "no"
IPV6INIT= "yes"
IPV6_AUTOCONF= "yes"
IPV6_DEFROUTE= "yes"
IPV6_FAILURE_FATAL= "no"
NAME= "enp0s3"
UUID= "933cdc9b-b383-4ddd-b219-5a72c69c9cf0"
ONBOOT= "yes"
HWADDR= "08:00:27:3F:AB:68"
IPADDR0= "192.168.1.150"
IPADDR1= "192.168.1.151"
IPADDR2= "192.168.1.152"
PREFIX0= "24"
GATEWAY0= "192.168.1.1"
DNS1= "192.168.1.1"
IPV6_PEERDNS= "yes"
IPV6_PEERROUTES= "yes"
As you can see, I have added two IP addresses: IPADDR1= "192.168.1.151" & IPADDR2= "192.168.1.152"
Similarly, you can add more ip addresses.
Finally, save and exit the file. Restart the network service for the changes to take effect.
The code is as follows:
Systemctl restart network
Now, let's check to see if an ip address has been added.
The code is as follows:
Ip addr
Sample output:
The code is as follows:
: lo: mtu 65536 qdisc noqueue state UNKNOWN
Link/loopback 00:00:00:00:00:00 brd 00:00:00:00:00:00
Inet 127.0.0.1/8 scope host lo
Valid_lft forever preferred_lft forever
Inet6:: 1/128 scope host
Valid_lft forever preferred_lft forever
2: enp0s3: mtu 1500 qdisc pfifo_fast state UP qlen 1000
Link/ether 08:00:27:3f:ab:68 brd ff:ff:ff:ff:ff:ff
Inet 192.168.1.150/24 brd 192.168.1.255 scope global enp0s3
Valid_lft forever preferred_lft forever
Inet 192.168.1.151/24 brd 192.168.1.255 scope global secondary enp0s3
Valid_lft forever preferred_lft forever
Inet 192.168.1.152/24 brd 192.168.1.255 scope global secondary enp0s3
Valid_lft forever preferred_lft forever
Inet6 fe80::a00:27ff:fe3f:ab68/64 scope link
Valid_lft forever preferred_lft forever
As you can see, a single network card already has three ip addresses.
Let's ping the new IP address:
The code is as follows:
Ping-c 4 192.168.1.151
Sample output:
The code is as follows:
PING 192.168.1.151 (192.168.1.151) 56 (84) bytes of data.
64 bytes from 192.168.1.151: icmp_seq=1 ttl=64 time=0.048 ms
64 bytes from 192.168.1.151: icmp_seq=2 ttl=64 time=0.075 ms
64 bytes from 192.168.1.151: icmp_seq=3 ttl=64 time=0.077 ms
64 bytes from 192.168.1.151: icmp_seq=4 ttl=64 time=0.077 ms
-192.168.1.151 ping statistics
4 packets transmitted, 4 received, 0% packet loss, time 2999ms
Rtt min/avg/max/mdev = 0.048 ms 0.069 ms 0.077 cusp 0.013
Ping-c 4 192.168.1.152
Sample output:
The code is as follows:
PING 192.168.1.152 (192.168.1.152) 56 (84) bytes of data.
64 bytes from 192.168.1.152: icmp_seq=1 ttl=64 time=0.034 ms
64 bytes from 192.168.1.152: icmp_seq=2 ttl=64 time=0.075 ms
64 bytes from 192.168.1.152: icmp_seq=3 ttl=64 time=0.073 ms
64 bytes from 192.168.1.152: icmp_seq=4 ttl=64 time=0.075 ms
-192.168.1.152 ping statistics
4 packets transmitted, 4 received, 0% packet loss, time 2999ms
Rtt min/avg/max/mdev = 0.034 ms 0.064 ms 0.075 max 0.018
If you want to use a different subnet, you need to change the PREFIX0=24 to a different subnet, such as PREFIX1=16.
For example, I want to add a class An address (* such as 10.0.0.1) to my network card.
The code is as follows:
TYPE= "Ethernet"
BOOTPROTO= "none"
DEFROUTE= "yes"
IPV4_FAILURE_FATAL= "no"
IPV6INIT= "yes"
IPV6_AUTOCONF= "yes"
IPV6_DEFROUTE= "yes"
IPV6_FAILURE_FATAL= "no"
NAME= "enp0s3"
UUID= "933cdc9b-b383-4ddd-b219-5a72c69c9cf0"
ONBOOT= "yes"
HWADDR= "08:00:27:3F:AB:68"
IPADDR0= "192.168.1.150"
IPADDR1= "192.168.1.151"
IPADDR2= "192.168.1.152"
IPADDR3= "10.0.0.1"
PREFIX0= "24"
PREFIX1=16
GATEWAY0= "192.168.1.1"
DNS1= "192.168.1.1"
IPV6_PEERDNS= "yes"
IPV6_PEERROUTES= "yes"
You can see that I have added a Class An address (10.0.0.1) with a prefix of 16.
Save and exit the file. Restart the network service, and then the new address for ping:
The code is as follows:
Ping-c 4 10.0.0.1
Sample output:
The code is as follows:
PING 10.0.0.1 (10.0.0.1) 56 (84) bytes of data.
64 bytes from 10.0.0.1: icmp_seq=1 ttl=64 time=0.097 ms
64 bytes from 10.0.0.1: icmp_seq=2 ttl=64 time=0.073 ms
64 bytes from 10.0.0.1: icmp_seq=3 ttl=64 time=0.074 ms
64 bytes from 10.0.0.1: icmp_seq=4 ttl=64 time=0.075 ms
-10.0.0.1 ping statistics-
4 packets transmitted, 4 received, 0% packet loss, time 3000ms
Rtt min/avg/max/mdev = 0.073 ms 0.079 ms
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