openstack-manuals/doc/user-guide-admin/section_nova_cli_floating_ips.xml

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<section xml:id="manage_ip_addresses"
    xmlns="http://docbook.org/ns/docbook"
    xmlns:xi="http://www.w3.org/2001/XInclude"
    xmlns:xlink="http://www.w3.org/1999/xlink" version="5.0">
    <title>Manage IP addresses</title>
    <para>Each instance can have a private, or fixed, IP address and a
        public, or floating, one.</para>
    <para>Private IP addresses are used for communication between
        instances, and public ones are used for communication with the
        outside world.</para>
    <para>When you launch an instance, it is automatically assigned a
        private IP address that stays the same until you explicitly
        terminate the instance. Rebooting an instance has no effect on
        the private IP address.</para>
    <para>A pool of floating IPs, configured by the cloud operator, is
        available in OpenStack Compute.</para>
    <para>You can allocate a certain number of these to a project: The
        maximum number of floating IP addresses per project is defined
        by the quota.</para>
    <para>You can add a floating IP address from this set to an
        instance of the project. Floating IP addresses can be
        dynamically disassociated and associated with other instances
        of the same project at any time.</para>
    <para>Before you can assign a floating IP address to an instance,
        you first must allocate floating IPs to a project. After
        floating IP addresses have been allocated to the current
        project, you can assign them to running instances.</para>
    <para>One floating IP address can be assigned to only one instance
        at a time. Floating IP addresses can be managed with the
            <command>nova *floating-ip-*</command> commands, provided
        by the python-novaclient package.</para>
    <procedure>
        <title>To list pools with floating IP addresses</title>

        <step>
            <para>To list all pools that provide floating IP
                addresses:</para>
            <screen><prompt>$</prompt> <userinput>nova floating-ip-pool-list</userinput></screen>
        </step>
    </procedure>
    <procedure>
        <title>To allocate a floating IP address to the current
            project</title>
        <step>
            <para>The output of the following command shows the
                freshly allocated IP address:</para>
            <screen><prompt>$</prompt> <userinput>nova floating-ip-pool-list</userinput></screen>
            <para>If more than one pool of IP addresses is available,
                you can also specify the pool from which to allocate
                the IP address:</para>
            <screen><prompt>$</prompt> <userinput>floating-ip-create POOL_NAME</userinput></screen>
        </step>
    </procedure>
    <procedure>
        <title>To list floating IP addresses allocated to the current
            project</title>
        <step>
            <para>If an IP is already associated with an instance, the
                output also shows the IP for the instance, thefixed IP
                address for the instance, and the name of the pool
                that provides the floating IP address.</para>
            <screen><prompt>$</prompt> <userinput>nova floating-ip-list</userinput></screen>
        </step>
    </procedure>
    <procedure>
        <title>To release a floating IP address from the current
            project</title>
        <step>
            <para>The IP address is returned to the pool of IP
                addresses that are available for all projects. If an
                IP address is currently assigned to a running
                instance, it is automatically disassociated from the
                instance.</para>
            <screen><prompt>$</prompt> <userinput>nova floating-ip-delete FLOATING_IP</userinput></screen>
        </step>
    </procedure>
    <procedure>
        <title>To assign a floating IP address to an instance</title>
        <step>
            <para>To associate an IP address with an instance, one or
                multiple floating IP addresses must be allocated to
                the current project. Check this
                with:<screen><prompt>$</prompt> <userinput>nova floating-ip-list</userinput></screen>In
                addition, you must know the instance's name (or ID).
                To look up the instances that belong to the current
                project, use the <code>nova list</code> command.</para>
            <screen><prompt>$</prompt> <userinput>nova add-floating-ip INSTANCE_NAME_OR_ID FLOATING_IP</userinput></screen>
            <para>After you assign the IP with <command>nova
                    add-floating-ip</command> and configure security group rules for the instance, the instance is
                publicly available at the floating IP
                address.
              </para>
        </step>
    </procedure>
    <procedure>
        <title>To remove a floating IP address from an
            instance</title>
        <step>
            <para>To remove a floating IP address from an instance,
                you must specify the same arguments that you used to
                assign the IP.</para>
            <screen><prompt>$</prompt> <userinput>nova remove-floating-ip INSTANCE_NAME_OR_ID FLOATING_IP</userinput></screen>
        </step>
    </procedure>
</section>