Guy’s Best Practice & Litmus Tests Ezine #10 – Assemble your toolkit!
There is no question, the right tool makes fixing problems a joy. Here is a wide variety of tools, I bet at least one will be new to you.
Contents for Ezine #10
The professional always has the right tool for the right job.
When ever you get a tool tip make a note of: ‘Where the executable comes from? Is it :
O.K, so you probably know about Ipconfig and the /all switch. But do you know about the new family of Ipconfig switches. Starting with Windows 2000 we have Ipconfig /registerdns; this switch saves a reboot when you change DNS settings of the TCP/IP properties. Registerdns contacts the DNS server and makes a host entry in the DNS database.
On several occasions, Ipconfig /flushdns has saved me a reboot. As the name of the switch suggests, it deletes stored addresses that could be preventing a connection. The scenario is you change a path to a distant machine, but you cannot connect because your machine has cached the old useless DNS entry.
Whilst Ipconfig /displaydns does not actually change anything, it is interesting to view the cached DNS sites. For the full list of switches, go to the command prompt and try Ipconfig /? See more about ipconfig in PowerShell 3.
Guy Recommends: The Free IP Address Tracker (IPAT)
Calculating IP Address ranges is a black art, which many network managers solve by creating custom Excel spreadsheets. IPAT cracks this problem of allocating IP addresses in networks in two ways:
For Mr Organized there is a nifty subnet calculator, you enter the network address and the subnet mask, then IPAT works out the usable addresses and their ranges.
For Mr Lazy IPAT discovers and then displays the IP addresses of existing computers. Download the Free IP Address Tracker
Ping is the best utility for instant connectivity. However, have you tried ping’s ‘big brother’ pathping? This is a better alternative than using ping -t when testing for intermittent connections. Incidentally pathping reminds of another useful command line utility: tracert (Trace route).
While ping and pathping are built-in to the operating system, FreePing is a wonderful third party utility for testing connectivity. Here is one of my – ‘And a tale goes with the tip’.
Back in the last century, one company I visited used FreePing as a primitive security measure. They wanted to catch thieves who were stealing RAM sticks. The security guard was given a FreePing console displaying all the machines in the company, and when a machine was switched off (to steal the RAM chips) he got a ‘net send’ message from FreePing. His team then reacted like a hit squad and went to trap the baddies.
The problem was that I had come to fix a server and no-one told me of the security plan. Guy turned off a machine he was working on only to be confronted by big men with baseball bats. There was a happy ending. Guy was released with no more than a fright and the very next week they caught two teenagers stealing the RAM sticks.
Best of all, you can download the full FreePing product from tool4ever at no charge. Or see my Took Kit page here:
Here is a little utility from the Resource Kit. Just double click the executable and Kerbtray appears down in the area I used to call systray, but is now an part of the screen officially named ‘the Navigation Area’ (down there by the clock).
Tell the truth Kerbtray could be more exciting, however it does at least confirm that Kerberos security tickets really do exist are not a figment of Microsoft’s imagination. Download Kerbtray here:
The idea is to test for rogue unsigned drivers. You may have noticed that with Windows 200x you get hardly any blue screens of death compared with NT 4.0. I guess we want to keep it that way, and thanks to sigverif, you can identify third party drivers that could have harmful effects on the operating system kernel.
The heart of the problem is that if a company writes a driver – say for scanner, then that driver has access to the operating system kernel. If the code is not written properly it could blue screen your machine. The deal between Microsoft and the driver manufactures is that each driver is submitted to Microsoft who test it. If it’s O.K. the driver gets a digital signature and passes the sigverif test.
Sigverif is one of those tools that is really well hidden, so if you have not seen it before, this is what you do: click on Start, Run, and type sigverif in the box.
See more interesting DNS, DHCP and IP articles