Networks

In a Nutshell

Each bwCloud-OS instance automatically receives a public IP address, valid for its entire lifetime (until deletion). Instances are also assigned a persistent FQDN based on their UUID and region. Domain hosting is not provided, but you can point your own domain to the instance’s FQDN using a CNAME record.

Networks & IP-addresses

Will my instance receive a public IP?

Yes. Every instance that is started in the standard way is dynamically assigned a publicly accessible IP address. Each region has (currently) different IP ranges from which public IPs are allocated. The current IP ranges are listed here.

How long does an IP remain assigned to my instance?

The assigned IP address remains assigned to an instance for its entire lifecycle. This means that the instance can also be stopped without the IP address being reassigned. Only when an instance is deleted ("terminated") is the IP released again after a short period of time and reassigned to another instance in the region.

Are Floating IPs also available for instances?

Currently Floating IPs are available only in certain regions (e.g., Freiburg). For a guide how to use them, see here.

Hostnames and Domains

Does bwCloud-OS also assign host names?

Yes, each running instance is assigned a generic hostname (FQDN) so that the VM can be reached via the network using a persistent identifier even if the IP address changes.

This consists of the UUID of an instance, the region in which it is running and the postfix .bw-cloud-instance.org. The generic host name is displayed in the overview of the running instances in the web dashboard. This FQDN is valid for the instance lifetime.

Here is an example: Let's say, the UUID of your instance is caffee-4242-2323-caffee and it is running in the bwCloud-OS region Mannheim. The generic hostname will be:

caffee-4242-2323-caffee.ma.bw-cloud-instance.org

Within an instanc the FQDN can be determined by:

# BWC_REGION="ma"

# FQDN="$(cat /var/lib/cloud/data/instance-id).${BWC_REGION}.bw-cloud-instance.org"

Can I get a domain via bwCloud-OS?

No, we do not offer domain hosting. However, every user is free to enter a CNAME in their home institution or even in any domain that points to the FQDN. Users can also set up DynDNS-like systems outside the cloud, which can be configured to the corresponding IP by their own VMs, similar to the procedure for the home network connection if this is made accessible via a persistent name.

How can I point a domain to an instance?

It should either be done dynamically or via a CNAME record to the FQDN of the VM. The assignment of a UUID to an instance is persistent (permanent), even if the instance is stopped - therefore the CNAME record of a domain can refer to the FQDN.

Can I get a certificate via bwCloud-OS?

No, we do not offer certificates. However, your instance can obtain certificates from other institutions (e.g. Let's Encrypt) using the CertBot.