Guide: Network Configuration by Region

This guide provides details of the VM networks in each bwCloud-OS region. It describes which networks are available by default, which can be requested, and how IPv4 and IPv6 connectivity is provided.

While core networking concepts are consistent across regions, available networks, IP address ranges, and access methods may differ. Please refer to the section for your specific region.

Freiburg

• Information for this region will be provided soon.*

Karlsruhe

The Karlsruhe region provides a default routed network, as well as additional networks that can be assigned to projects upon request.

Default Network

• All projects have access to the default network default-network.
• Instances connected to this network receive:
  • A public IPv6 address
  • A private IPv4 address

This is a routed network using an OpenStack router connected to an external provider network.

• IPv6: Direct public connectivity
• IPv4 (egress): Provided via SNAT through the router
• IPv4 (ingress): Not available by default (see IPv4 Ingress via Floating IPs)
• This Network is shared between all projects

IPv4 Ingress via Floating IPs

• Floating IPs are allocated from the external network provider-network.
• They can be assigned to projects upon request via a support ticket.

Once assigned, a Floating IP can be associated with an instance to provide IPv4 ingress connectivity.

Seperated Networks

If you require a seperated Broadcast Domain you can request one via a support ticket.

The network will:

• receive a separate private IPv4 Subnet
• receive a separate public IPv6 Subnet
• have a separated Broadcast Domain only accessible by authorized projects
• always use up at least one public IPv4 used for the virtual Router

Migration from Gen2 to Gen3

The Karlsruhe region is currently operating two environments in parallel:

• Gen2 (legacy cloud)
• Gen3 (current bwCloud-OS environment)

This setup allows users to migrate their instances and data from Gen2 to Gen3.

• The coexistence period will last until 31. August 2026.

After the transition period:

• All IP addresses (Routers and Floating IPs) from provider-network will be migrated to a new IPv4 Subnet.
• This migration will be performed by administrators; no user action is required.
• During the Migration all Floating IPs will be redistributed and some minor connection interruptions will happen.

Mannheim

The Mannheim region provides a default routed network, as well as additional networks that can be assigned to projects upon request. Both IPv6 and IPv4 connectivity options are available, depending on the selected network.

Default Network

• All projects have access to the default network routed_default_net.
• Instances connected to this network receive:
  • A public IPv6 address
  • A private IPv4 address

This is a routed network using an OpenStack router connected to an external provider network:

• IPv6: Direct public connectivity
• IPv4 (egress): Provided via SNAT through the router
• IPv4 (ingress): Not available by default (see IPv4 Ingress via Floating IPs)

📌 Note: This network extends the legacy IPv6-only network in the Mannheim region, which did not provide IPv4 connectivity. Before requesting an IPv4 address via a support ticket, please ensure that the combined connectivity is not already sufficient for your use case.

IPv4 Ingress via Floating IPs

• Floating IPs are allocated from the external network provider_default_net.
• They can be assigned to projects upon request via a support ticket.

Once assigned to a project, a Floating IP can be associated with an instance to provide IPv4 ingress connectivity.

Flat External Networks

• There are also flat external networks available, such as provider_interim_net .
• They can be assigned to projects via a support ticket.

Instances connected directly to this type of network receive:

• A public IPv4 address
• A public IPv6 address

This enables dual-stack public connectivity (IPv4 and IPv6) without the need for Floating IPs.

Migration from Gen2 to Gen3

The Mannheim region is currently operating two environments in parallel:

• Gen2 (legacy cloud)
• Gen3 (current bwCloud-OS environment)

This setup allows users to migrate their instances and data from Gen2 to Gen3.

• The coexistence period will last until 31. August 2026.
• During this period, provider_interim_net is used as the flat external network.

After the transition period:

• All dual-stack IP addresses from provider_interim_net will be migrated to provider_default_net. This migration will be performed by administrators; no user action is required.
• Projects requiring a flat external network will be assigned provider_default_net.

📌 Note: We do not recommend allocating Floating IPs from the provider_interim_net, because they will be lost after the transition period. Instead, request and associate them from provider_default_net.

Ulm

• Information for this region will be provided soon.*