Network security

Network security is handled on different levels depending on the class of traffic. The different classes are separated by VLANs and protected from Internet traffic by a firewall on the gateway in a Flying Circus location.

VLAN classes and gateway firewall

Frontend network (fe)

Nodes providing services intended for the general public (users of applications hosted within the Flying Circus) have one or more IPv4/IPv6 addresses in this network.

Traffic to addresses in this network is freely allowed by the gateway firewall.

Customers should only bind services to this IP address that are intended to be accessed from the internet. Backend services should be bound to the server network.

Server network (srv)

All nodes have an address in the server network. This is used by applications for internal communication, e.g. application servers communicating with their database.

Server networks use a mixture of public and private IP addresses. Outbound traffic is generally possible and will be masqueraded on the gateway firewall if necessary.

Inbound traffic will be blocked on the gateway firewall with the following exceptions:

  • 22/tcp (ssh)

  • 80/tcp (http)

  • 443/tcp (https)

  • 5666/tcp (nrpe)

  • 8140/tcp (puppet)

Ports 80 and 443 are for backend web services like access statistics and are expected to be turned off in the future.

Storage network (sto)

This network is used for SAN traffic (mainly for storage servers to provide the iSCSI volumes to KVM hosts or the backup service). It is only accessible to ring 0 machines owned by the Flying Circus but not customer-owned equipment or virtual machines.

This network uses private IPv4 addresses that are not routed from the internet. Traffic from outside this network is not allowed.

Management network (mgm)

This network is used for management purposes only: access to base management controllers (IPMI), switch consoles etc.

It uses private IPv4 addresses that are not routed from the internet. Traffic from outside this network is not allowed.

Machine firewall