Physical networks

The physical network in our public datacenter is implemented using physically separated switches per layer 2 segment (VLAN) with a hot-spare for each switch type.

The frontend (FE) and server-to-server (SRV) networks run on 1G infrastructure, where as the storage networks are connected with 10G ports. The datacenter uplink from our routers uses redundant 2x10G connectivity.

Routers are attached to upstream ports provided by the data center, a dedicated management link, and a link with tagged VLANs for everything else.

Logical networks


The following VLANs and logical networks are in use:

MGM - Management, purely for administrative purposes. This VLAN connects switch management ports, Remote Access Controllers, and additional access to server OSes via SSH. Not accessible from the outside world, private IPv4 address space. DNS example: switch.mgm.rzob.gocept.net.

FE - Frontend, for customer application traffic. This VLAN connects to machines that provide customers’ applications to the public. This network is switched to the virtual machines and leverages completely public traffic. The DC firewalls do not filter this. Customer applications are free to use any ports they like but must be careful opening them. VMs can filter this network locally. All VMs receive a NIC on this VLAN but not necessarily IPv4 or IPv6 addresses if they do not provide public traffic. DNS example: vm00.fe.rzob.gocept.net.

SRV - Server to server communication. Used for customer application components to talk to each other, e.g. database traffic and for management purposes on the application level. This network is firewalled from the internet at our DC edge firewalls and allows only HTTP/S and SSH traffic. Additionally VMs can filter this traffic locally and only allow arbitrary traffic from VMs belonging to the same project by default. This network is used on all VMs and has IPv4 (usually private) and IPv6 addresses allocated automatically. DNS example: vm00.srv.rzob.fcio.net or simply vm00.fcio.net.

STO - Storage communication. Used by the virtualization and backup servers to access the network storages where the VM disk images as well as object storage gateways (RadosGW) are located. DNS example: filer.sto.rzob.gocept.net.

STB - Storage backend communication. Used by the storage layer for replication and self-management. DNS example: filer.stb.rzob.gocept.net.

Individual VMs that run management services, like monitoring, may get bridged into the additional VLANs or granted firewall exceptions as necessary.

The routers suppress routing of traffic on VLANs that are “martian”, e.g. frontend traffic injected on the server-to-server network or private addresses from the internet.

Services that require tight control are bound to listening IP addresses on only those networks but then can get relaxed ACL rules making configuration simpler and easier to understand.

Local ports

Your application is generally free to use any open port on a machine above 1024. Especially if you run a component that has a registered, well-known port, please use that.

However, custom applications may run into the trouble of colliding with other components. For that we guarantee that the ports 61000-61999 will never be used by our managed components, nor by the kernel when assigning dynamic ports.