Hands on: File-sharing made easy

In the absence of a Windows domain, ACLs make peer-to-peer file-sharing more scalable and secure, but they can also cause problems. For example, if I have logged on to my PC as Alan and try to access files on another which has the default Administrator account defined, I won’t be allowed.

In which case, I need to either log on as Administrator (Windows will usually prompt for a username and password just for the file access), or I have to make sure there’s a matching user account (Alan, in this example) on each PC on the network.

Defining common user accounts on each PC and setting access rights can solve a lot of file-sharing issues, especially where you’re mixing Windows 2000 and XP PCs together.

However, there’s another complicating factor that can affect networks where you’re trying to share files between XP Pro and XP Home PCs – and it’s called, paradoxically, Simple File Sharing (SFS).

Far from simple
When Microsoft introduced Windows XP, it decided that ACL security might be too complicated for home users, so it modified it to provide SFS. Optional in XP Pro, but not XP Home, SFS automatically assigns rights to the built-in Everyone group when a new share is defined.

Moreover, it modifies the file-sharing dialogue so that the only options are to either allow read-only access or let other network users modify the contents of a share. It also changes the way remote users are authenticated. Instead of their login name, remote users are always authenticated using the built-in Guest account.

The upshot is that you don’t really have to manage the file-sharing process, and there’s no need to configure matching user accounts on every PC. Simply share a folder and anyone on the network can access it.

However, folders are either shared or not, with only very crude controls over what remote users are allowed to do. Plus it can lead to other problems, especially when upgrading older PCs and mixing different versions of Windows together.

Convert from Fat to NTFS (for example, when upgrading to Windows XP from Windows 98), and the Everyone group isn’t automatically created. You’ll then find that you can’t access the shares on the upgraded PC, although the converted PC can still connect to shares on others.

Fortunately, there’s an easy fix for this. Stop sharing the folders concerned and configure them again under XP. But even on new PCs, simple file sharing can cause problems. For example, it stops administrative shares (used by some software distribution tools) from working and blocks remote Registry access.

With XP Home there’s not much you can do other than live with these limitations. But with XP Pro you can turn SFS on and off, depending on what other versions of Windows you’re using.

To do this double-click My Computer and select Folder Options from the Tools menu. Click the View tab and look for the entry marked ‘Use simple file sharing (Recommended)’. It's usually the last entry in the list.

So if you’re having problems sharing files between XP Home and XP Pro PCs, try enabling Simple File Sharing on the XP Pro systems.

Conversely, if you only have XP Pro, or if you want to add Windows 2000 to the mix, then disable it to manage the access control lists and troubleshoot any file-sharing problems yourself.

Power to the network
I recently sampled a couple of Netgear XE104 Wall-Plugged Ethernet Switches and, despite some initial scepticism, they worked well.

About the size of a mains power adapter, these little boxes contain a four-port Ethernet switch with an integrated three-prong plug on the back to enable them to be inserted directly into a mains wall socket. But that’s not all.

The XE104 is a Homeplug device that uses the mains wiring to effectively bridge switches. This facility is handy for creating a home network; in my case, connecting to the internet from a PC in the upstairs bedroom.

Of course, a wireless would do the trick, but that would have meant finding and installing a suitable adapter, and the PC involved already had an integrated wired Ethernet interface.

Instead, I plugged one of the Netgear switches into an outlet downstairs, where my router is located, and another into a socket in the upstairs bedroom. They immediately found each other over the household wiring, as indicated by a bright blue LED, giving an 85Mbits/sec connection with no bother.

At about £60 for each of the switches, they’re not cheap and you do need at least two. But it does take all the hassle out of setting up a cabled network, and I’ll be looking more at this kind of approach in future issues.

Plug in a couple of Netgear Wall-Plugged Ethernet Switches and you’ll get an instant network using your mains wiring as a bridge

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