Chapter 16. File Services (NFS and FTP)

In this chapter, we will cover services used to share files, including NFS (Network File System) and FTP (File Transfer Protocol). Specifically, this chapter will cover configurations to apply firewall rules to an NFS file server, allow forwarded or DNAT style rules through a firewall using NFS and FTP, and rules to allow you to restrict access to these servicesas well as troubleshooting steps for all of these.

More information on the NFS protocol can be obtained from RFCs 1094, 1813, and 3010. FTP is covered in RFC 959.

Recall that in earlier chapters, the problem-solving methodology we recommend requires that before moving on to a higher level in the OSI model, you must rule out any root causes in the preceding layers. If you have not already done so, please refer back to Chapter 5 for a discussion of the OSI model and how the problem-solving methodology is applied to it. Then work through and isolate the problem using the other chapters in this book before moving on to this one. The protocols in this chapter are somewhat complex and, as such, might prove to be difficult to troubleshoot without ruling out other root causes.