I’m running the trial version of Business Protection (not the plus version) to test the product as I need basic antivirus protection on my WHS2011 server and clients. WHS2011 is based on Server 2008 R2 Foundation. Avast seems to work well, with one issue as set out below on the server and one issue on Win 7 x64 clients. It would appear that this version of avast has some sort of inconfigurable firewall built into it, which is odd as I thought only the plus version has it. Symptoms:

Server - no antivirus installed, I can access SQL database without any problems at all. Install the BP consol - still works fine. Install antivirus and reboot - SQL inaccessible. Disable all shields - inaccessible. Uninstall antivirus and reboot - SQL is accessible again. I’ve had a look at the Windows firewall and can’t see any changes being made there. This issue is apparent even with no antivirus installed on the client (see next problem).

Client - running the free version of avast (latest version 6), I can access my networked HP printer / scanner just fine. Deploy the BP version - inaccessible. Still doesn’t work even with all shields disabled. Uninstall and revert to the free version - works again.

I cannot see anything in the BP consol which even hints at a firewall, but it is clearly blocking traffic somehow. Any suggestions on what to do? If I can get around this issue, I think it will be an effective solution to my requirements.

The good news is that after much investigation, I’ve managed a workable solution. The bad news is I still don’t understand what caused the problem in the first place, so maybe someone can shed some light on the issue for me.

The client side issue was solved by reinstalling the printer software (twice). No idea why this fixed it as it was working 100% alongside the free avast client before installing the BP client, but so far so good. Similar to the server issue below, there does not appear to be any sign of ports being altered in the firewall, so it’s quite strange.

With the SQL connection, I finally established that port 1434 was being blocked by Windows firewall (this SQL connection is for MyMovies if anyone has a similar problem in future). What confuses me is why that port gets blocked on the server as soon as the avast antivirus component is installed, but gets allowed as soon as it is uninstalled again. However, looking at the firewall configuration, that port is nowhere near the ones used by avast (8731, 8372 and 25322) and there is no specific entry dealing with port 1434 in the firewall configure.

So, very odd - but it now works, which is good news for those WHS users looking for an antivirus solution - it’s a bit pricey versus the old WHS-specific one and doesn’t come with any dashboard plugin, but it’s easy enough to administer via remote access and the web interface so I’ll live with it until the next (hopefully) version of WHS-specific software is available.