Test Layout

I have done a lot of work with small and mid-sized wired networks, but I have only worked with single access point wireless networks until recently. The first thing I noticed is that the documentation on configuring wireless networks for multiple access points is poor. So, with the idea of helping others, here is what I’ve figured out. For the purposes of my examples, I’m assuming that the clients will be accessing the wireless access point (WAP) by using a shared-key (password) and that all users will be using the same key. The use of 802.1x for authentication is beyond the scope of what I’m dealing with. Vendors use slightly different terminology for the same scenario. I've attempted to use generic terminology that is similart to most vendors. You can often use just the WAP functionality of a wireless router. However, many of these do not have as many wireless configuration options. If you use a wireless router as a second WAP, be sure that you disable DHCP on the device. Only th...

Every once in a while you run into a situation where two applications are attempting to use the same port number. Of course this means that one application is blocked out and doesn't function properly. In a perfect world, we'd know all the ports used by various pieces of software on our servers and instantly understand where the conflict is. However, we don't live in perfect world, and some apps pick random port numbers. On a Windows server, you friend is netstat -ab > C:\portlist.txt . This command dumps a list of ports and the processes using those ports to a text file. Then you can find out which process is conflicting with your failed service/application. I used this just today to find out that a watchguard logging process was using port 4101 that a BES routing service wanted to use. I've also used it in the past to find out that Symantec Mail Security was randomly selecting a port in the low 10xx range that another application wanted to use.

ODBC connections allows a Windows computer to connect to a data source. Typically the datasource is a database. In a 32-bit version of windows, you just create the ODBC connection and it works. In a 64-bit version of windows, then it is more complex. In a 64-bit version of Windows, you need to create an ODBC connector to that matches the application. For a 64-bit application, you create a 64-bit ODBC connection. For a 32-bit app, you create a 32-bit ODBC connection. The most common problem is creating an ODBC connection by using the ODBC Data Source Administrator tool in control panel and then you are unable to see of view the ODBC connection from a 32-bit application. The ODBC Data Source Administrator tool that you can open from control panel creates only 64-bit ODBC connections. To create 32-bit ODBC connections you need to run Odbcad32.exe from the C:\Windows\SysWoW64 folder.

McAfee sent out a bad update yesterday that wiped out a Windows System file (svchost.exe) and rendered Windows very unhappy. The system I was dealing with initially lost network connectivity and many programs stopped running properly. I ran a Repair installation for XP to fix the issue. They now supply a tool to fix the problem: http://vil.nai.com/vil/5958_false.htm You figure that sort of thing would show up in testing. XP SP2 and XP SP3 were affected.

Ok, so let's say, you accidentally deleted a group. Or, thought it wasn't needed and turns out that it was. People can no longer access files, and you can't remember exactly which files the group was assigned access to. The good news is that you can recover from this. Option 1 - Restore AD objects from backup If you have a system state backup of a DC (and you should!!), you can restore the deleted object from backup. Then you mark it as authoritative. However, to have group memberships restored correctly, you need to perform an ugly process where objects are restored twice to make sure the links are correct. Also the DC needs to be down during this mess. Doable, but not the preferred option. Detailed info: http://support.microsoft.com/kb/840001 Option 2 - Reanimiate the deleted object Yes, just like a zombie, you can bring back an object from the dead. And also like a zombie, it is a shadow of its former self. Only some properties are kept in the deleted object. When you re...

I have one ISP where we have intermittent problems delivering messages to mailboxes hosted by that ISP. It is something related to DNS lookups, because when I clear the cache on our DNS server, the problem goes away. So, presumably it's changes on their end that cause the issue. By default the Windows DNS server caches DNS lookups for 24 hours. However, I don't want to be manually clearing the cache on this each time the error occurs (or wait up to 24 hours to automatically resolve). The solution: modify the cache TTL. In all of the forward lookup zones that you create, you can set the TTL for the zone or individual records. However, in the cache, you can't set the TTL by using the DNS Manager console. You can either use dnscmd.exe or edit the registry. In HKLM\SYSTEM\CurrentControlSet\Services\DNS\Parameters, create a REG_DWORD value named MaxCacheTtl and provide a value in seconds. I did not find any documentation saying that this registry key works in Windows Server 2008...

Purchased a new brand of print server this week. As usual, every product has it's quirks. In this case, I needed to know the port name used for LPR/LPD printing on this device. The print server came with a tiny (literally physically tiny, like you get with kids toys) set of instructions that worked great only for the basic windows printing scenario. Unfortunately, I was in the ancient NetWare printing zone (NetWare 5.1, shiver...). So, the basic manual did not provide enough info. Step 2....Vendor web site. Nope, same tiny manual as came with the box. Step 3....Google. Unfortunately the product is sold by so many places that all I got was sale listings. I was about to give up when it occurred to me that perhaps there was some thing on the CD that came with the product. Turns out there is a one hundred and some page manual that covers just about everything conceivable, but only on the CD.