Managing IP Addresses

Each Linode Compute Instance is equipped with several IP addresses, which enable it to be accessible over the public Internet and to other Linode services. This guide covers how to manage these IP addresses (including viewing, adding, removing, transferring, or sharing them) through the Cloud Manager.

Viewing IP Addresses

1. Log in to the Cloud Manager and click the Linodes link in the sidebar.

2. Click on your Linode Compute Instance from the list to view more details.

3. Within the top Summary section, you can view the primary IPv4 and IPv6 addresses.

4. To view all of your IP address for this Instance (along with any associated rDNS values), click the View all IP Addresses link or navigate to the Network tab and review the IP Addresses section.

Types of IP Addresses

IPv4

• Public IPv4 Address: All Compute Instances are created with at least one public IPv4 address, which enables your applications to be accessible over the Internet. Additional addresses can be provided with technical justification.

• Private IPv4 Address: Optionally, private IPv4 addresses can be assigned to a Compute Instance. This allows it to connect to other services located in the same data center, such as NodeBalancers or other Compute Instances.

  Note

  All private IPs in the same data center can communicate with each other over the private network. This means a Compute Instance’s private IP address is accessible to all other Instances in that data center. It’s recommended to set up firewall rules for your Linode to secure its network traffic. See our firewall guides for details on setting up firewall rules. In many cases, using Private VLANs is preferred over private IPv4.

IPv6 Addresses

• IPv6 SLAAC Address: This is the main IPv6 address used to communicate over the public Internet and with other services in the same data center. All Compute Instances are assigned a single SLAAC address, which cannot be removed or transferred. Additional SLAAC addresses cannot be provided. If you need an additional IPv6 address, consider using a /64 range (see below).

• IPv6 Link Local: This IPv6 address is assigned to each Compute Instance and used for internal routing.

• /64 Routed Range: This is the most common range provided to our customers and sufficient for most applications that require additional IPv6 addresses. A single /64 range provides 18,446,744,073,709,551,616 addresses that can be used when configuring the applications within your system. See the Linux Static IP Configuration guide for instructions on configuring specific addresses from a range. By default, up to one /64 range can be added per customer per data center.

• /56 Routed Range: These larger ranges are typically only required by specialized systems or networking applications. A single /56 range provides 4,722,366,482,869,645,213,696 addresses that can be used when configuring the applications within your system. See the Linux Static IP Configuration guide for instructions on configuring specific addresses from a range. By default, up to one /56 range can be added per customer per data center.

• /116 Pool: (4,096 addresses) An IPv6 pool is accessible from every Linode on your account within the assigned data center. Addresses from that pool can be configured on each Linode within that data center. This can enable features like IPv6 failover. By default, up to one /116 pool can be added per customer per data center.

  Caution

  The IPv6 /116 prefix has been deprecated and is not available in the Toronto, Atlanta, Sydney, or Mumbai data centers. To add a /116 pool in a supported data center, contact our Support team with your request.

Adding an IP Address

Follow the instructions below to add an public IPv4, private IPv4, or IPv6 range to your Compute Instance. By default, up to one /64 and /56 range can be added per customer per data center.

1. Log in to the Cloud Manager and click the Linodes link in the sidebar.

2. Click on your Linode Compute Instance from the list and navigate to the Network tab.

3. Click the Add an IP Address button under the IP Address section. This displays the Add an IP Address panel.

4. Within the form, select the type of IP address (or range) you wish to add. If you aren’t sure, review the Types of IP Addresses section and consider your own use case.

   

5. Click the Allocate button to add the additional address. If you receive a message similar to the following, you need to contact our Support team to request the IP address. Make sure to include any additional information or technical reasoning for the request.

   Additional IPv4 addresses require technical justification. Please open a Support Ticket describing your requirement

   Once the IP address or range has been added, it should be visible in the IP Address section.

6. To make sure the new IP address is configured within the internal system of the Compute Instance, verify that Network Helper is enabled and reboot the Compute Instance.

   If Network Helper is turned off and you’ve configured a static IP address, you need to update the configuration files with the new IP address or enable Network Helper.

Note

Due to the impending exhaustion of the IPv4 address space, Linode requires users to provide technical justification for additional public IPv4 addresses. If you have an application that requires multiple IP addresses, consider using an IPv6 /64 range instead.

Configuring rDNS

The ability to point a domain name to an IP address is referred to as forward DNS resolution. Reverse DNS (rDNS) lookup is the inverse process, where an IP address resolves to a domain name. Official Internet documents state that “every Internet-reachable host should have a name,” and that the name should match a reverse pointer record. (See RFC 1033 and RFC 1912.)

You are able to configure rDNS (or reset it) through the Cloud Manager using the instructions below:

Note

Before setting reverse DNS, verify that you have created a matching forward DNS record for the IP address. For instructions, see Adding DNS Records. If you use a third-party DNS provider, create the forward DNS record with your provider’s management tool.

1. Log in to the Cloud Manager and click the Linodes link in the sidebar.

2. Click on your Linode Compute Instance from the list and navigate to the Network tab.

3. Select the Edit RDNS menu option for the IP address to which you’d like to add a reverse pointer record, as shown in the below image.

4. The Edit Reverse DNS menu appears. Enter a domain as shown in the below image. If you wish to reset the rDNS back to its original *.members.linode.com (or *.ip.linodeusercontent.com) domain, make sure this field is empty.

   

5. Click Save to make the change.

   Note

   If you receive the message that no match was found, this indicates that you need to update the forward DNS for this domain. Make sure the domain or subdomain in question resolves to the IP address for which you are trying to set the reverse DNS. If you’ve recently made a DNS change, you may need to wait 24-48 hours for it to propagate.

You can verify the reverse DNS entry was properly submitted within the IP addresses table under the Reverse DNS column.

Deleting an IP Address

1. Log in to the Cloud Manager and click the Linodes link in the sidebar.

2. Click on your Linode Compute Instance from the list and navigate to the Network tab.

3. Select the Delete menu option for the IP address you’d like to remove

4. A pop-up confirmation dialog appears. Click the Delete Range button to confirm the request.

5. To make sure the IP address is removed from the internal system of the Compute Instance, verify that Network Helper is enabled and reboot the Compute Instance.

   If Network Helper is turned off and you’ve configured a static IP address, you need to update the configuration files to remove the IP address or enable Network Helper.

Transferring IP Addresses

If you have two Compute Instances in the same data center, you can use the IP transfer feature to move or swap their IP addresses. This feature is especially useful when replacing one Compute Instance with another. It allows you to quickly move the IP addresses to the new Instance without needing to manually adjust DNS records with the new addresses.

Note

This process only transfers IPv4 addresses and IPv6 ranges, not IPv6 SLAAC addresses. See Transferring an IPv6 SLAAC Address below for a workaround.

1. Log in to the Cloud Manager and click the Linodes link in the sidebar.

2. Click on your Linode Compute Instance from the list and navigate to the Network tab.

3. Press the IP Transfer button in the IP Addresses table.

4. Locate the IP address or range you would like to transfer and select an action from the dropdown menu:

   • Move To: moves the IP address to another Compute Instance. When choosing this option, select the destination Compute Instance in the next dropdown menu that appears. If you are moving a public IPv4 address, there needs to be at least one remaining public IPv4 address on the source Compute Instance.
   • Swap With: swaps the IP addresses of two Compute Instances. When choosing this option, select the destination Compute Instance in the next dropdown menu that appears. Then select the IP address (belonging to the destination Compute Instance) you would like to swap with the originally selected IP address.

   Note

   The IP Transfer form only displays Compute Instances hosted in the same data center as the current Instance.

5. Click Save to transfer the requested IPs.

6. To make sure the new IP addresses take affect within the internal configuration of each Compute Instance, verify that Network Helper is enabled and reboot the affected Instance(s). It may take up to 1-2 minutes for the transfer to take affect.

   If Network Helper is turned off and you’ve configured a static IP address, you need to update the configuration files with the new IP addresses or enable Network Helper.

   Note

   If the IP is unreachable after a few minutes, you may need to notify the router directly of the IP change with the arp command run on your Compute Instance:

   arping -c5 -I eth0 -s 198.51.100.10 198.51.100.1
   ping -c5 198.51.100.10 198.51.100.1
   

   Replace 198.51.100.10 with your new IP address, and 198.51.100.1 with the gateway address listed in your Networking tab under the Default Gateways column of the IP Addresses table.

Transferring an IPv6 SLAAC Address

IPv6 SLAAC addresses are not able to be transferred between Compute Instances. If this is something you need to do, consider moving the applications you want to be hosted on that IPv6 address over to the Compute Instance containing that IPv6 address. One way to accomplish this is to clone the disks containing the data. See the Cloning to an Existing Linode section of the Cloning a Linode guide. After the cloning process has completed, transfer any required IPv4 addresses.

Configuring IP Sharing

IP sharing, also referred to as IP failover, is the process by which an IP address is reassigned from one Compute Instance to another in the event the first one fails or goes down. If you’re using two Instances to make a website highly available with Keepalived or a similar service, you can use the Cloud Manager to configure IP failover.

Note

Not all data centers currently support IP Sharing. Review the Configuring IP Failover to learn more about IP Sharing and IP failover support.

1. Log in to the Cloud Manager and click the Linodes link in the sidebar.

2. Click on your Linode Compute Instance from the list and navigate to the Network tab.

3. Click the IP Sharing button under the IP Addresses section.

4. The IP Sharing form appears. Select the Compute Instance you would like to share an IP address with.

5. Click Save to enable IP Sharing.

6. After enabling IP Sharing in the Cloud Manager, the next step is to configure a failover service (such as Keepalived) within the internal system on each affected Compute Instance. For more information, see our guide on Configuring IP Failover.

Now, when a failover service such as Keepalived detects failure of your chosen Compute Instance, its IP address will be assigned to the new Instance to avoid an interruption in service.

Note

IP sharing does not change ownership of the origin IP address, and the IP address will continue to belong to the same origin Compute Instance. By default, IP sharing alone does not change the behavior of how traffic reaches your Compute Instances and the capability must be further configured with tools like Keepalived.