How do I add an additional IP address to /etc/network/interfaces?
I have an extra IP address available to my server, and so I need to assign it in the interfaces file. At the moment, I've got this:
auto lo iface lo inet loopback auto eth0 iface eth0 inet static address aaa.aaa.aaa.aaa netmask 255.255.254.0 gateway bbb.bbb.bbb.bbb dns-nameservers ccc.ccc.ccc.ccc ddd.ddd.ddd.ddd eee.eee.eee.eee dns-search vps-number.com
What do I add to assign my new IP address (fff.fff.fff.fff)? And how do I then restart it to accept the new configuration?
auto lo iface lo inet loopback auto eth0 iface eth0 inet static address aaa.aaa.aaa.aaa netmask 255.255.254.0 gateway bbb.bbb.bbb.bbb dns-nameservers ccc.ccc.ccc.ccc ddd.ddd.ddd.ddd eee.eee.eee.eee dns-search vps-number.com auto eth0:0 iface eth0:0 inet static address fff.fff.fff.fff netmask 255.255.254.0
Then you can run
sudo ifup eth0:0to bring it up and
sudo ifdown eth0:0to bring it down.
This is outdated variant with aliases. Use below one with "ip addr" instead.
It may be old (and maybe outdated), but there's nothing wrong with using this method, since it was not marked 'deprecated' and there's no plan for it being removed in the near future. IMHO this method is cleaner and safer than the others (see the Wilmer's answer and its comments).
P.S If using `auto eth1`(it didnt on AWS) does not working use as in the example `auto eth0:0`.
For an extra IP address, I usually add:
up ip addr add fff.fff.fff.fff/prefixlen dev $IFACE
to the bottom of the
iface eth0 inet staticstanza for future reboots and then run the command
sudo ip addr add fff.fff.fff.fff/prefixlen dev eth0again manually to activate it directly.
If your netmask is
I'd love to know if there's a better way, though.
thank you so much, the accepted approach doesn't work for bonding (**ifenslave**), but this does!
`up` is problematic as network-online.target does not wait for it. systemd services like nginx will fail to bind on IP added by `up` on startup time
You can just have repeated iface stanzas for the same interface. Example from https://wiki.debian.org/NetworkConfiguration#Multiple_IP_addresses_on_one_ :
auto eth0 allow-hotplug eth0 iface eth0 inet static address 192.168.1.42/24 gateway 192.168.1.1 iface eth0 inet static address 192.168.1.43/24 iface eth0 inet static address 192.168.1.44/24 # adding IP addresses from different subnets is also possible iface eth0 inet static address 10.10.10.14/24
So just the solution above but drop the
:xsuffix, which as Heihachi points out is outdated.
ip addrsuggestion is the worst. It's ugly and incomplete, as you'll have to also add a
ifdownwon't work very cleanly.)
From the documentation at your link, talking about the most modern method for doing things (called iproute2): _Note however that this method is **dangerous**! Certain driver/hardware combinations may sometimes fail to bring the link up if no labels are assigned to the alias interfaces._ Considering that it's official documentation saying that the new way isn't such reliable, I'd prefer to stick with the working deprecated one.
Upvote because of official and precise documentation reference, but not for "a better solution", since it's marked as dangerous in the official documentation.
@reallynice Reasonable point, though IMHO if this causes problems on a system that sounds to me like a buggy kernel/driver. I've been using multiple IP addresses on a single interfaces without the ugly :0/:1/etc aliases for years.(Also I'm pretty sure the solution from the Wiki is functionally equivalent to Robbie's solution above.)
@Wilmer I have a vmxnet3 device (VMware ESXi 6.5) on Ubuntu 16.04, and I could only get the new way to bring up the first device. Dropping the :x suffix was clearly not better for me. The documentation cleared up an error I was getting with the :x suffix though.
The last known issue with `iproute2` method was in 2015. And the legacy method (have you noticed the name?) didn't work for me on Debian Stretch. It seemed like the later options (from `eth0:0`) overrided the earlier ones (`from eth0`). That is, after `systemctl restart networking` I ended up with just the second IP (the first IP was detached).
...Then, in Debian Stretch (Ubuntu 16.04 Xenial) they added: 'Multiple "iface" stanzas can be given for the same interface, in which case all of the configured addresses and options for that interface will be applied when bringing up that interface. [...] It can also be used to configure multiple addresses of the same type on a single interface.'