Cloud IPs

Cloud IP addresses are publicly routed IPv4 addresses that can be instantly mapped to Cloud Servers, Load Balancers or Cloud SQL instances.

Cloud IPs belong to an account and can be mapped to resources on the same account. They are added to an account by “creating” them and removed by “destroying”.

Mapping a Cloud IP to a Cloud Server

All servers have private IPv4 address in the 10.x.x.x range, accessible only from within the Brightbox network. Once a Cloud IP is mapped to a server, packets to and from the Cloud IP are translated using NAT to the server’s private IP address.

Outgoing connections from the server to the Internet are translated to the first Cloud IP mapped to the server. If no Cloud IP is mapped, a shared IP address is used.

Incoming and outgoing connections to and from the server’s private IP (such as from other servers on the Brightbox network) are unaffected by Cloud IP mappings.

Remapping a Cloud IP address will interrupt any established connections using the address.

Mapping a Cloud IP to a Load Balancer

Cloud IPs can be mapped to Load Balancers, allowing seamless transition from one server to many.

Load Balancers are inaccessible until a Cloud IP is mapped to them. Once a Cloud IP is mapped to a load balancer, packets to the Cloud IP are translated to the Load Balancers. Load Balancers do not make outgoing connections to the Internet themselves, so no outgoing translation occurs.

Mapping a Cloud IP to a SQL Instance

Cloud IPs can be mapped to Cloud SQL instances. SQL instances are inaccessible until a Cloud IP is mapped to them.

A note on Cloud Server interfaces

Cloud IPs are actually mapped to an interface on a server. The API accepts a server identifier as the destination and maps the IP to the first available interface.

Cloud IPs are mapped directly to load balancers as they do not have interfaces like Cloud Servers.


The first Cloud IP mapped to a Cloud Server is accessible using the DNS record (where srv-xxxxx is the server identifier and gb1 is the region code).

If no Cloud IP is mapped, the record fails to resolve (returning a NXDOMAIN).

Reverse DNS

The default reverse DNS of a Cloud IP is currently of the form

Custom reverse DNS for Cloud IPs is covered in the DNS reference and in the CLI Reverse DNS Guide.

Port Translation

Port Translation can be used to change the destination port of a tcp or udp connection coming into a Cloud IP. It can be used to emulate having multiple private IP addresses on a Cloud Server. It’s commonly used to host multiple TLS/SSL sites on the same server.

Port Translation applies only to connections coming into a Cloud IP - they do not affect outgoing connections from the Cloud Server.

See the Port Translation guide for a walk through on how to use them.

Port Translation and Firewalling

As with Cloud IP mappings, Port Translation acts on traffic before the Cloud Firewall. So, for example, if you’re translating port 443 on a Cloud IP to port 2443 on a Cloud Server, your firewall rules would need to allow port 2443.

Port Translation and Load Balancers

Cloud IPs with port translations can of course be mapped to load balancers too. You need to specify your load balancer listeners to use the translated port. So, if you’re translating port 443 to port 2443 then your load balancer needs a listener on port 2443.

Last updated: 28 Apr 2016 at 00:39 UTC

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