I was fortunate enough to attend Michael Warfield’s talk on DNS security this past Monday. If you don’t know Mike, he is a crazy smart dude who gives spectacular presentations. Can’t recommend him enough! Mike has been at the forefront of the IPv6 movement, and has given a number of IPv6 presentations in the past few months. The video from one of those presentations (Brave New World of IPv6 ) was just posted to the Internet, and I thought I would pass on the link. Mike is an incredible presenter, and you will definitely take away a boatload of information from each and every chat of his you attend. We are now officially out of IPv4 addresses, so I would be willing to bet that IPv6 will get a lot of attention this year. Get you learn on now!
I just put up a new article a simple and easy way to encrypt data on Linux, OS X and Windows desktops and servers. The article describes Truecrypt, and shows how it can be used to set up an encrypted device on Linux, Windows and OS X hosts. If you have sensitive data on your machine, you NEED this awesome piece of FREE software. It rocks!
Microsoft Windows has all kinds of tools buried throughout the Windows directory. Several of these tools allow you to display and debug DNS and IP issues, which can be handy when you get a call from a customer that they can’t access your systems. If you need to display all of the entries your Windows host is caching, you can open cmd.exe and run the ipconfig utility with the “/displaydns” option:
Windows IP Configuration 184.108.40.206.in-addr.arpa ---------------------------------------- Record Name . . . . . : 220.127.116.11.in-addr.arpa. Record Type . . . . . : 12 Time To Live . . . . : 84375 Data Length . . . . . : 4 Section . . . . . . . : Answer PTR Record . . . . . : localhost google.com ---------------------------------------- Record Name . . . . . : google.com Record Type . . . . . : 1 Time To Live . . . . : 143 Data Length . . . . . : 4 Section . . . . . . . : Answer A (Host) Record . . . : 18.104.22.168 .......
To flush the cached DNS settings you can run ipconfig with the “/flushdns” setting:
Windows IP Configuration
Successfully flushed the DNS Resolver Cache.
If your host is configured to register it’s name dynamically with DNS, you can use the the “/registerdns” option to register your host with DNS and to refresh your DHCP lease:
In a follow up post I will discuss Microsoft’s DNS server and some tools you can use to debug it.