IFSM 430 Lab exercise Using the Windows XP PCs in Kadena lab. What's the Windows computer's name? ______________ Ways to find out: (try them all) 1. Properties of My Computer icon | ComputerName 2. Start|Programs|Accessories|SystemTools|SystemInformation 3. In cmd prompt (Start|Run|cmd): nbtstat -n oops, that's not set up on these computers (it would show work group too) What's the computer's IP address? ___________________________ 1. Open the Local Area Connection icon in system tray| Support 2. In cmd prompt: ipconfig Default Gateway is router this computer talks to for external network connections: its IP: __________________________ Assigned by DHCP means the computer gets it IP address from a DHCP server computer somewhere each time it boots. This is called dynamic IP as opposed to static IP where the IP address is configured into the computer and it always uses that address. Dynamic IP is more flexible for network administration but servers need a static known address. What's the DHCP server:____________________ 1. Click Details of the Local Area Connection Status window. 2. ipconfig /all Notice that the same IP (same machine) is the DHCP server and the default gateway. What's the computer's DNS server or servers? (where it has Internet domain names like yahoo.com translated to IP addresses) ______________________ 1. on the Network Connection Details window 2. ipconfig /all Host name (Internet name) may or may not be same as Windows computer name (Microsoft's NetBIOS LAN networking). Is TCP/IP networking working on the computer? 1. ping localhost ping sends a message to, and gets response from, a computer. localhost is synonym for self. If TCP/IP is not installed or running, ping will indicate. Where is the ping reply coming from:____________ (this is a spceial IP address is always associated with the localhost.) What is the amount of time each ping takes:_______________ What are the Min, Max, and Average times:____________________________ What are the time units:__________________ Can the computer communicate with another computer on the LAN with TCP/IP? 1. Ping the default gateway by its IP address. What is the amount of time each ping takes:_______________ What are the Min, Max, and Average times:____________________________ Ping your neighbor's computer. IP addresses starting with 192.168. are special addresses for internal networks not directly accessible from the Internet. These computers are "hidden" from the Internet by the router/default gateway which does a translation to and from the 192.168 address to an Internet accessible IP address (this process is called NAT). Can the computer communicate with another computer on a different network? We don't have another network :( Ping one of the DNS servers (see if there's a connectivity problem with it). Ping some computer on the Internet. 1. ping 66.218.71.80 What is the amount of time each ping takes:_______________ What are the Min, Max, and Average times:____________________________ Can the computer communicate with another computer by its Internet domain name? (test if domain name service is working) 1. ping www.yahoo.com Where is the reply coming from:___________________ What are the Min, Max, and Average times:____________________________ What's a long time to ping? ping www.cenpac.net.nr It's in Nauru, an island in Pacific. What are the Min, Max, and Average times:____________________________ ping chels.anadyr.ru Extreme Siberia. What are the Min, Max, and Average times:____________________________ A computer can be configured so that it doesn't respond to a ping request. That can help security but harm diagnostics. Tools exist to ping a range of IP addresses to find live machines ("ping sweep"). For example, all IPs from 192.168.0.1 to 192.168.0.254 could be pinged. What's the route a packet takes across the Internet? tracert www.yahoo.com Shows the times to go to each router along the route from your computer to the destination. The big gap is the traversal under the Pacific, which is approximately ______________. Might also cross the USA in one jump. Notice that some routers have names instead of only IP addresses. The names can give a clue of where the router is or the network provider (the Internet's backbones), any examples: ____________________________________________________ tracert www.nypl.org New York Public Library Goes from your computer to default gateway, to several routers at KDD (our ISP) in Naha (seems like and probably) these are the hops that are 40 ms away, then to mainland Japan and more routers (70 ms), then jumps the puddle to West coast and more routers, then jumps to East coast,... tracert www.fudan.edu.cn Fudan University in Shanghai, 500 miles to the west. What is the physical path being taken? Established (i.e. active, connected) TCP ports can be seen by the netstat command. Start your web browser, connect to some web site, then do netstat. What is the local port ("local address") for this connection:_____________ "Foreign address" is the name and port of this connection:_____________________________ netstat -a shows listening ports too. What are the TCP listening ports that have known names:______________________________________ Use the telnet command to connect to the Linux server: telnet 192.168.0.197 login name is ifsm430 Password is Use the nmap command to do a port scan of the Linux: nmap localhost What services are running and on what ports: ________________________________________________________ _______________________________________________________ Use nmap to do a port scan of another computer, use the IP address of your Windows PC: nmap your.IP.addr What services are running and on what ports: ________________________________________________________ _______________________________________________________ Use nmap to do a port scan of the printer: nmap 192.168.0.205 What services are running and on what ports: ________________________________________________________ _______________________________________________________