Robert McMurray

As evidenced by my How to Use Managed Code (C#) to Create an FTP Authentication Provider with Dynamic IP Restrictions walkthrough and my other FTP authentication extensibility walkthroughs, I spend a lot of time trying to find ways to prevent unauthorized access to my FTP server while still allowing valid users to have easy access to their site content. Today's blog discusses several of the ideas that I like to use on my FTP servers.

One of the changes that we made in FTP 7.0 and FTP 7.5 was to remove recursive directory listings, which are commonly retrieved by typing "ls -lR" from a command-line FTP client, which should send a command like "NLST -lR" over FTP to the server. There were several reasons why we decided to remove recursive directory listings, but the main reason was simply to reduce CPU usage on the server; recursive directory listing requests take a lot of resources to fulfill. With that in mind, both FTP 7.0 and FTP 7.5 will ignore the recursive switch on directory requests.

Even though IIS 7 with its new XML-based configuration settings has been around for a while, I was going through some old directories on one of my computers the other day and I stumbled across an image that I had labeled "Metabase Corruption." I have kept that image around for the past decade or so because it's one of the few actual examples of metabase corruption that I have actually verified, although there have definitely been more cases than just the ones that I have seen. But I thought that it might make for a good blog entry to explain the origins of the term "Metabase Corruption" and what that means to you if you're using a version of IIS that is earlier than IIS 7.

I had not intended to do a series on this subject when I wrote my original Merging FTP Extensibility Walkthroughs blog post, but I came up with a scenario that I felt was worth sharing. I recently posted the following walkthrough on the learn.iis.net web site:

I had a great question in the publishing forums on forums.iis.net, where someone was asking if FTP 7 supported the XCRC command. The short answer is that the XCRC command is not supported, but I came up with a way to create an FTP provider that supports something like it. Since it was a rather fun code sample to write, I thought that I'd turn it into a blog.

I have mentioned in previous blog posts that I tend to write many of my blog posts and walkthroughs for IIS.NET based on code that I’ve written for myself, and today’s blog post is the story of how one of my samples saved my rear over this past weekend.

Over the past several months I’ve been publishing a series of walkthroughs that use the extensibility in FTP 7.5 to create a several custom providers for a variety of scenarios, and today I posted my most recent entry in the series:

Today's blog post needs to have a disclaimer right up front - I freely admit I'm not a Mac OS X expert, so I may not have everything 100% correct in this post. But I've seen a lot of questions on forums.iis.net that discuss using IIS WebDAV with Mac OS X, so I thought that I'd share a few of the things that I've noticed. Just the same, if I were writing a formal walkthrough I would have said something like, "Microsoft is not responsible for the behavior of Apple's Mac family of products. The information that is provided in this topic is provided to assist Mac OS X users connect to IIS using WebDAV."