Here is a list of command line utilities that can be helpful while diagnosing and troubleshooting network connectivity issues on Windows Vista & XP:

1. Getmac – Displays MAC (Media Access Control) address & the associated transport name in TCP/IP for network adapters on a system

2. Hostname – displays the name of the machine on the network

3. Ipconfig –displays IP address, subnet mask and gateway for each network adapter associated with the TCP/IP, release and renew IP address from DHCP and flush and register DNS in DNS server

4. Nslookup – name server lookup to determine various types of records from the default or specified DNS server

5. Net – used to update, fix, or view the network and its related settings

6. Netstat – displays active connections and the type of protocol used along with the port numbers

7. Netsh – view and alter the network configuration settings (found under Network Connections in the Control Panel)

8. Pathping – combines functionality of traceroute and ping.

9. Nbtstat – displays protocol statistics and current TCP/IP connections using NetBIOS over TCP/IP.

10. Ping – A utility that forwards data packets to check the quality of a link or verify the connection of a machine to the Internet

11. Route – Add, remove and modify routing table of OS

12. Tracert – displays the number of hops and the the time taken between each hop from host to destination