Configuring additional IP addresses
Configuring additional IP addresses
Upon ordering a Dedicated Server or VPS you will receive one IPv4 address and one
/64
IPv6 subnet. As an example, this could be the IPv4 address192.51.100.10
and the IPv6 subnet2001:0db8:2a02:c200::/64
.Your server comes pre-configured with this IPv4 (
192.51.100.10
) and one IPv6 address (2001:0db8:2a02:c200:0000:0000:0000:0001
). Additional IPv4 addresses can be ordered by contacting us atinfo@cairowebdesign.com
or through our support tickets at: https://www.cairowebdesign.com/billing/contact.php These additional IPv4 address will not be added to your system automatically but will have to be configured manually.The following will give an overview on how to configure additional IP addresses on the most popular operating systems. The server used in these examples has the primary IPv4 address
192.51.100.10
and will receive the additional IPv4 addresses192.51.100.42
and192.0.2.23
. As a general rule we recommend configuring these addresses with a netmask of255.255.255.255
(/32
) and/64
respectively and without adding a new gateway.
CentOS 6.x
CentOS has all its network interface configuration files stored in
/etc/sysconfig/network-scripts/
. In order to configure additional IPv4 addresses, one virtual interface per additional IPv4 address has to be created. If the main interface is e.g.eth0
, the virtual interfaces would be namedeth0:0
,eth0:1
,eth0:2
and so on. Their configurations reside in individual configuration files namedifcfg-eth0:0
,ifcfg-eth0:1
,ifcfg-eth0:2
receptively.
#/etc/sysconfig/network-scripts/ifcfg-eth0:0
DEVICE=eth0:0
BOOTPROTO=none
ONBOOT=yes
IPADDR=192.51.100.42
NETMASK=255.255.255.255
#/etc/sysconfig/network-scripts/ifcfg-eth0:1
DEVICE=eth0:1
BOOTPROTO=none
ONBOOT=yes
IPADDR=192.0.2.23
NETMASK=255.255.255.255Additional IPv6 addresses can be specified using the variable
IPV6ADDR_SECONDARIES
in the interface's primary configuration file (/etc/sysconfig/network-scripts/ifcfg-eth0
in case ofeth0
). Multiple addresses are separated by a white space:
#/etc/sysconfig/network-scripts/ifcfg-eth0
...
IPV6ADDR_SECONDARIES=2001:0db8:2a02:c200:0000:0000:0000:0002/64 2001:0db8:2a02:c200:0000:0000:0000:0003/64
...
To apply the changes, restart the network service:
service network restartCentOS 7.x / Fedora
The network interface configuration files of both CentOS 7.x and Fedora are stored under
/etc/sysconfig/network-scripts/
. Additional IPv4 addresses can be added to the respective interface's configuration file by using variables of the patternIPADDR0
,IPADDR1
,IPADDR2
andPREFIX0
,PREFIX1
,PREFIX2
etc., in case of e.g.eth0
this would be/etc/sysconfig/network-scripts/ifcfg-eth0
:
#/etc/sysconfig/network-scripts/ifcfg-eth0
...
IPADDR0=192.51.100.42
PREFIX0=32
IPADDR1=192.0.2.23
PREFIX1=32
...The old method using virtual interfaces as employed in CentOS 6.x and described above will also still work.
Additional IPv6 addresses can be specified using the variable
IPV6ADDR_SECONDARIES
in the interface's primary configuration file (/etc/sysconfig/network-scripts/ifcfg-eth0
in case ofeth0
). Multiple addresses are separated by a white space:
#/etc/sysconfig/network-scripts/ifcfg-eth0
...
IPV6ADDR_SECONDARIES=2001:0db8:2a02:c200:0000:0000:0000:0002/64 2001:0db8:2a02:c200:0000:0000:0000:0003/64
...
To apply the changes, restart the network service:
service network restartcPanel
With cPanel there is no need to deal with configuration files. Log in to WHM and navigate to "IP Functions" » "Add a New IP Address". Enter the IP address, select subnet mask
255.255.255.255
and click "Submit"
Debian / Ubuntu (until 17.04)Debian's and Ubuntu's network interface configuration is stored in
/etc/network/interfaces
. Additional IP addresses can be assigned by adding them in separateiface</code sections. The following adds
192.51.100.42
and192.0.2.23
toeth0
whose primary address is192.51.100.10
:
#/etc/network/interfaces
auto eth0
allow-hotplug eth0
iface eth0 inet static
address 192.51.100.10
netmask 255.255.255.255
gateway 192.51.100.1
iface eth0 inet static
address 192.51.100.42
netmask 255.255.255.255
iface eth0 inet static
address 192.0.2.23
netmask 255.255.255.255
...Additional IPv6 addresses are configured similarly:
#/etc/network/interfaces
...
iface eth0 inet6 static
address 2001:0db8:2a02:c200:0123:4567:89ab:0001
netmask 112
gateway fe80::1
accept_ra 0
autoconf 0
privext 0
iface eth0 inet6 static
address 2001:0db8:2a02:c200:0000:0000:0000:0002
netmask 64
...
To apply the changes, restart the networking service:
service networking restart
Or:
ifdown eth0; ifup eth0
Ubuntu (17.10 and above)In Ubuntu beginning with version 17.10, you can find the network configuration in the file
/etc/netplan/01-netcfg.yaml
. With this method you can assign additional IPv4 and IPv6 addresses to the interfaceeth0
. Additionally to the main IPv4 address192.51.100.10
and the first IPv6 address of your IPv6 network, you might configure the additional IPv4 addresses192.51.100.42
and192.0.2.23
and the additional IPv6 addresses2001:0db8:2a02:c200:0000:0000:0000:0002
and2001:0db8:2a02:c200:0000:0000:0000:0003
in the areaaddresses:
below ofeth0:
. It is important to keep the correct indentation!#/etc/netplan/01-netcfg.yaml network: version: 2 renderer: networkd ethernets: eth0: match: macaddress: 00:50:56:3d:c3:aa addresses: - 192.51.100.10/24 - 192.51.100.42/24 - 192.0.2.23/24 - 2001:0db8:2a02:c200:0000:0000:0000:0001/64 - 2001:0db8:2a02:c200:0000:0000:0000:0002/64 - 2001:0db8:2a02:c200:0000:0000:0000:0003/64 gateway4: 192.51.100.1 gateway6: fe80::1 nameservers: search: [ invalid ] addresses: - 79.143.183.251 - 79.143.183.252 - 2a02:c205::1:53 - 2a02:c205::2:53
To apply the changes, please enter this command:
netplan apply