Dealing with Firewall-Protected Networks

Network firewalls are set up to make sites inside them harder to penetrate without proper authorization. Encryption and PIN-based challenge-response systems usually are part of them. Some firewalls refuse to allow incoming connections that are not encrypted, including X-Windows sessions. Cooperation between an encryption agent, such as SSH, and the X-Windows display server is necessary to accomplish this. Similarly, cooperation is needed between a file transfer mechanism and an encryption agent to effect file transfers through firewalls.

Since the procedures enforced by firewalls are under the control of the owning institutions, NERSC cannot offer much general advice on how to work with them. The most useful source of how-to information for a firewall-protected network is the network security administrator.