Figure 6-11: WFAS Inbound Rules in .NET

Create QR in .NET Figure 6-11: WFAS Inbound Rules

Figure 6-12: WFAS Outbound Rules If you are having connectivity problems and disabling Windows Firewall solves them, look at your firewall settings. In some cases, restoring the defaults solves your immediate problems, but this is a simplistic approach. The settings were changed for a reason. You need to investigate further. 7 gives you the tools to do so. For example, restoring the defaults does not permit you to use Ping to test continuity on your network, and it would not be a good idea to disable firewalls on all the computers on your subnet. Instead, you need to add rules that enable ICMPv4 and ICMPv6 packets to pass through your firewall: To permit ICMPv4 and enable you to ping other computers by their IPv4 addresses, enter the following in an elevated command prompt on all computers on your network: netsh advfirewall firewall add rule name="ICMPv4" protocol=icmpv4:any,any dir=in action=allow To permit ICMPv6 and enable you to ping other computers by their IPv6 addresses, enter the following in an elevated command prompt on all computers on your network: netsh advfirewall firewall add rule name="ICMPv6" protocol=icmpv6:any,any dir=in action=allow Quick Check How do you restore the default firewall settings Quick Check Answer In Control Panel, click System and Security. Click Windows Firewall. In the left pane, click Restore Defaults. EXAM TIP Remember that in Windows 7, you cannot ping other computers on your network by default.

Accessing Network Statistics If you are debugging performance issues as opposed to troubleshooting a total connectivity failure, you need information about the various protocols that implement network connectivity. The Netstat command-line tool displays active connections, the ports on which the computer is listening, Ethernet statistics, the IP routing table, and IPv4 and IPv6 statistics. Used without parameters, the command displays active connections, as shown in Figure 6-13.

Figure 6-13: The Netstat command displays active connections The syntax of the Netstat command is as follows: netstat [-a] [-e] [-n] [-o] [-p Protocol] [-r] [-s] [Interval] The parameters implement the following functions: -a Displays all active connections and the Transmission Control Protocol (TCP) and User Datagram Protocol (UDP) ports on which the computer is listening. -e Displays Ethernet statistics, such as the number of bytes and packets sent and received. This parameter can be combined with -s. -n Displays active connections. Addresses and port numbers are expressed numerically and no attempt is made to determine names. -o Displays active connections and includes the process ID (PID) for each connection. You can find the application based on the PID on the Processes tab in Windows Task Manager. This parameter can be combined with -a, -n, and -p. -p protocol Shows connections for the protocol specified by the protocol variable, which can be tcp, udp, tcpv6, or udpv6 If this parameter is used with -s to display statistics by protocol, which can be tcp, udp, icmp, ip, tcpv6, udpv6, icmpv6, or ipv6. -s Displays statistics by protocol. By default, statistics are shown for the TCP, UDP, ICMPv4, ICMPv6, IPv4, and IPv6 protocols. The -p parameter can be used to specify a set of protocols. -r Displays the contents of the IP routing table. This is equivalent to the route print command. interval Displays the selected information periodically. The number of seconds between each display is defined by the interval parameter. If this parameter is omitted, Netstat prints the selected information only once.

Netstat provides statistics for the following:

The name of the protocol (TCP or UDP) The IP address of the local computer and the port number being used The IP address and port number of the remote computer The state of a TCP connection Note MORE INFO: TCP CONNECTION STATES For more information about the states of a TCP connection, see http://support.microsoft.com/kb/137984 This article was written some time ago but remains relevant to Windows 7.

For example, to display both the Ethernet statistics and the statistics for all protocols, enter the following command: netstat -e -s To display the TCP statistics for the IPv4 protocol, enter the following command: netstat -s -p tcp Figure 6-14 shows the TCP statistics for the IPv4 protocol on the Canberra computer.

Figure 6-14: TCP protocol statistics for IPv4 Practice: Configuring IPv4 Network Connectivity and Setting up ICS In this practice, you configure the Canberra and Aberdeen computers with static IPv4 addresses, configure the firewalls on both computers to allow Ping commands, and test connectivity. You then reconfigure the computers to obtain their IPv4 configuration automatically and set up ICS in Canberra so both computers can access the Internet through Canberra's wireless link.

EXERCISE 1: ConfiguringIPv4 Connectivity This exercise assumes that Canberra and Aberdeen are Configured to obtain their IPv4 configurations automatically (the default). If they are both physical computers, they need to be connected on the same Ethernet network either by a switch or hub or by a crossover Ethernet cable. To configure IPv4 connectivity, proceed as follows: Log on to the Canberra computer using the Kim_Akers account. Open an elevated command prompt. To allow ICMPv4 traffic through the Canberra firewall, enter netsh advfirewall firewall add rule name="ICMPv4" protocol=icmpv4:any, any dir=in action=allow. 4. To configure static IPv4 configuration, enter netsh interface ipv4 set address "local area connection" static 10.0.0.11 255.255.255.0 10.0.0.1. Currently, there is no DNS service on your private network, so there is no point configuring a DNS setting. Note that if you are using virtual machines, the connection to your private wired network may have a name other than Local Area Connection. 5. Enter ipconfig. Your screen should look similar to Figure 6-15. 1. 2. 3.

Figure 6-15: Static configuration of the Canberra computer 6. Remaining logged on to the Canberra computer, log on to the Aberdeen computer using the Kim_Akers account. 7. Open an elevated command prompt. 8. To allow ICMPv4 traffic through the Aberdeen firewall, enter netsh advfirewall firewall add rule name="ICMPv4" protocol=icmpv4:any, any dir=in action=allow. 9. Open Network And Sharing Center. Click Change Adapter Settings. 10. Right-click the Ethernet adapter Local Area Connection and choose Properties. 11. Click Internet Protocol Version 4 (TCP/IPv4) and click Properties. 12. Configure the connection as shown in Figure 6-16.

Figure 6-16: Configuring the Aberdeen computer 13. Click OK. Click Close. 14. In the elevated command prompt, enter ipconfig. Your screen should look similar to Figure 6-17.

Figure 6-17: Static configuration of the Aberdeen computer 15. Enter ping 10.0.0.11. Your screen should look similar to Figure 6-18.

Figure 6-18: Pinging the Canberra computer from the Aberdeen computer 16. On the Canberra computer, enter ping 10.0.0.21. Check that you have two-way connectivity. 17. Restore dynamic IPv4 configuration on both the Canberra and Aberdeen computers. EXERCISE 2: Configuring ICS on the Canberra Computer In this exercise, you install ICS on the Canberra computer. This enables Internet access on Aberdeen and ensures that Canberra can supply DNS and DHCP services on the network. The exercise requires that Canberra can access the Internet wirelessly and is therefore optional. If you also have a wireless adapter on the Aberdeen computer, ensure that this is disabled. Ensure that both Aberdeen and Canberra are Configured to obtain IPv4 settings automatically. 1. 2. 3. 4. 5. If necessary, log on to the Canberra computer using the Kim_Akers account. Open Network And Sharing Center. Click Change Adapter Settings. Right-click the wireless adapter Wireless Network Connection and choose Properties. Click the Sharing tab. Select the Allow Other Network Users To Connect Through This Computer's Internet Connection check box, as shown in Figure 6-19. Click OK.

Figure 6-19: Allowing other computers to use the Canberra Internet connection 6. 7. 8. 9. 10. If necessary, log on to the Aberdeen computer using the Kim_Akers account. Open Network And Sharing Center. Click Internet Options. Click the Connections tab and ensure that Never Dial A Connection is selected. Click LAN Settings. In the Local Area Network (LAN) Settings dialog box, under Automatic Configuration, clear the Automatically Detect Settings and Use Automatic Configuration Script check boxes. 11. Under Proxy Server, clear the Use A Proxy Server For Your LAN check box. The LAN Settings dialog box should look similar to Figure 6-20. Click OK.

Figure 6-20: The LAN Settings dialog box on an ICS client computer 12. Click OK to close the Internet Properties dialog box. 13. Open Windows Internet Explorer. You should have Internet connectivity. If not, run Windows Network Diagnostics. 14. Open an elevated command prompt (if necessary). Enter ping canberra. You now have a DNS service and can resolve computer names to IPv4 addresses.