Overview

Physical networks

The physical network in our public datacenter RZOB is implemented using physically separated switches per layer 2 segment (VLAN) with a hot-spare for each switch type. In WHQ, we operate multiple layer 2 segments using the same physical switches, using VLANs within the switches for logical separation, but with cold-spares instead of hot-spares.

The frontend (FE) and server-to-server (SRV) networks run on 1G infrastructure, whereas the storage networks are connected with 10G links. In RZOB our routers have redundant 2x10G connectivity to our uplink provider. In WHQ our routers have a redundant 2x1G link to our uplink provider, however this provider only has non-redundant 2.5G connectivity itself.

In all locations, routers are connected to the datacenter uplink, the frontend network, the server-to-server network, and the management network. In RZOB a dedicated physical interface is used for each of these networks. In WHQ, all of these networks are delivered over a single physical interface using tagged VLANs.

Logical networks

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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.

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, however the default system firewall running locally on VMs blocks inbound connections. Customer applications are free to use any ports they like. These ports must be listed in the firewall configuration in order to receive inbound connections. 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.fcio.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 „martian“ traffic which is on the wrong VLAN, e.g. frontend traffic injected on the server-to-server network or private addresses from the internet.

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.