Adding an IP address

If you've been assigned one or more additional IP addresses, here is how to add them.

Immediate configuration

You can use the ip command to make an additional IP address work immediately:

# ip address add 85.119.82.35/32 dev eth0

This address should now respond to ping and be completely usable (unless you have firewalling preventing that).

This configuration won't last past the next reboot however, so you now need to configure the change permanently.

Permanent configuration

Debian / Ubuntu

First open your interfaces file for editing:

# nano /etc/network/interfaces

You should see your main IP address described for IPv4 and IPv6. The IPv4 part looks something like:

    # The primary network interface
    auto eth0
    iface eth0 inet static
    address 85.119.82.34
    netmask 255.255.248.0
    gateway 85.119.80.1

Go to the end of the file and add information about your new IP. It doesn't need a gateway and you can use 255.255.255.255 for netmask:

    # The secondary network interface
    auto eth0:0
    iface eth0:0 inet static
    address 85.119.82.35
    netmask 255.255.255.255

For each additional IP, use eth0:1, eth0:2 etc.

Once you're finished, press Ctrl-X and save your file.

Shutdown and boot

If you want to test your permanent configuration then you'll need to shut down and boot your VPS again to ensure it comes up properly.

Due to a curiosity of the way Xen creates virtual machines, the next time you want to restart your VPS you should do a shut down and then a boot, rather than a reboot. If you reboot then Xen will only route IP addresses to you that you had last time it was booted, i.e. not any that you've had added since. If you forget and reboot anyway then you can restore the additional IP address's route by shutting down and booting again as described.

# shutdown now

You will then need to boot your machine by logging in via the Xen Shell console. Get your details from the BitFolk Panel:

$ ssh you@you.vps.bitfolk.com

Once logged in you will see the Xen command line prompt. Try

Xen shell> boot

If it complains that an instance already exists, and you've waited sufficiently long that the machine should have shut down, do

Xen shell> destroy

then

Xen shell> boot

You can now log back in to your VPS and your new IPs should work.