I cannot contact external servers/services

Problem

I have to contact an external server from within the HPC nodes, but it does not work, what can I do?

Solution

Network connectivity is restricted. You can connect to the Emmy and Grete login nodes from any remote host, while the SCC Legacy login nodes require connecting from GÖNET directly or via VPN. Outgoing connections on login nodes are restricted to SSH, FTP, HTTP, HTTPS, and native rsync (with a url like rsync://...; this is insecure, so we recommend only using rsync over SSH which is the default and most commonly used mode). Outgoing connections on compute nodes require the -C inet slurm option to use a caching proxy and are restricted to FTP, HTTP, and HTTPS. Contact our support if you need to connect to ports other than these.