Chapter 10: Network Naming Pg 349 - End

WINS

• LMHOSTS: 
• contains a list of the NetBIOS names and corresponding IP addresses of the hos systems on the network 
• work exactly the same as the DNS HOSTS file
• WINS: Windows Internet Name Service
• let NetBIOS hosts register their names with just the one server
• eliminates the need for broadcasting and thereby reducing NetBIOS overhead substantially
• enables NetBIOS name resolution across routers
• enables NetBIOS to function in a routed network 
• WINS Proxy Agent: 
• forwards WINS broadcasts to a WINS server on the other side of the router

Configuring WINS Clients

• configure the IP address of a WINS server in its WINS settings under Network Properties
• windows system will look for a WINS server to register its NetBIOS name 
• if it finds a WINS server, it will register its NetBIOS name to the WINS server
• if it doesn't it will automatically start broadcasting its NetBIOS name 
• you can add WINS information to DHCP if necessary

Troubleshooting WINS

• most WINS problems are NetBIOS problems
• most common problem is having two systems share the same name
• can use nbstat to help deal with NetBIOS problems 
• -c switch tells nbstat to check the current NetBIOS name cache 

Diagnosing TCP/IP Networks

• most TCP/IP problems come from improper configuartion 
• use the same steps no matter what the error 
• check the network connetions and protocols
• Steps:
• Diagnose the NIC: use ping with the loopback address to determine if the system can send an receive packets
• type ping 127.0.0.1 or ping localhost 
• if you get an error, check the NICs driver and replace it if necessary
• Diagnose Locally: ping a few neighboring systems by both IP address and DNS name
• use the net view command to see if the other local systems are visible 
• if you can't ping by DNS, check the DNS settings
• if you can't see the network using net view you may have a problem with your NetBIOS settings 
• Check IP address and subnet mask: ensure you have the right IP address and subnet mask. If using DHCP, renew the lease. 
• Run netstat: run netstat with no options at all and with the -s option. Running netstat with no options shows all the current connections to the sytem. 
• Run netstat -s: Displays several statistics that can help diagnose problems. If the display shows you are sending but not receiving, it is likely that there is a broken network cable.
• Diagnose to the Gateway: Ping the local interface and then the one to the internet. If you can't ping the router, it is either down or there is no connection to it. 
• Diagnose to the Internet: Ping an address on the internet, try several if the first one does not work. run tracert to mark out the entire route the ping packet traveled between you and whatever you were trying to ping. 

Things to Remember:

1. netBIOS uses a flat name space whereas DNS servers use a hierarchial name space.
2. the DNS root directory is represented by a dot (.)
3. To see the DNS cache on a Windows system, run the command ipconfig /displaydns at the command prompt. 
4. The HOSTS file is checked first when trying to resolve to FQDN to IP address.
5. The MX record is used by mail servers to determine where to send e-mail
6. the command ipconfig /flushdns eliminates the DNS cache.
7. the tool to use for querying DNS server functions is nslookup.
8. A DNS server stores the IP addresses and FQDNs for the computers within a domain in the forward lookup zone.