--- a/net.rst	Tue Mar 23 11:29:27 2010 +0200
+++ b/net.rst	Wed Mar 24 12:06:30 2010 +0200
@@ -6,6 +6,34 @@
 
 User - none, password - none, phone - '*99***1#'.
 
+* DNS to IP address.
+
+  $ nslookup example.com
+
+* IP to DNS address.
+
+  $ nslookup 192.168.1.1
+
+* NetBIOS to IP address.
+
+By nbtstat.exe command from MS you can print NetBIOS name cache with
+name-to-IP address mappings:
+
+  $ nbtstat -c
+
+* List of NetBIOS name.
+
+  $ nbtstat -r
+
+* List of open port.
+
+** Windows.
+
+  cmd> netstat        # with DNS name resolution, TCP only
+  cmd> netstat -n     # without name resolution, TCP only
+  cmd> netstat -a -n  # TCP and UDP
+  cmd> netstat -s     # show IP, ICMP, TCP, and UDP statistics.
+
 * How disable IPv6?
 
 ** Debian kernel 2.6/Ubuntu ("official" method)/Fedora Core.