Almost all HPC systems at NHR@FAU use private IP addresses that can only be accessed directly from within the FAU.There are three options for logging in to the clusters from outside the university: Use a VPN (Virtual Private Network) connection. Use IPv6. The cluster frontends have world-visible IPv6 addresses. Use our “dialog server” cshpc.rrze.fau.de. The dialog server is the only HPC machine with a public IPv4 address. cshpc is a Linux system that is open to all HPC accounts. From this machine, you can log into any NHR@FAU system. A more complete description can be found on our documentation pages. Whichever option you choose, you need to use SSH. Please consult our extensive SSH documentation pages for details.