The average round trip time is 23ms. This tells you how long it takes for data to move between the source and target, and back again.
2. What does a successful or unsuccessful "ping" tell you?It identifies that the target machine is up and my machine can connect to it.
3. Using the 'nslookup' command find the DNS name for IP: 128.208.100.109tess.ischool.washington.edu
4. Is the IP number 128.95.256.34 a valid address? Why or why not?No, this is not valid because each of the four octets must be between 0 and 255.
5. What is the IP address for citrix.ischool.washington.edu? Which tool did you use to find this answer?I used nslookup to find the address - 128.208.102.151. Ping could also be used to get the same result.
6. Why in general is it better to use a DNS name rather than an IP number?It's easier to remember the DNS name, and if the target machine is receiving a dynamic address through DHCP, the DNS server will point to the correct machine IP address if given the name.
7. In what rare situation could using an IP number enable you to connect to a desired host, when using the DNS name did not?If the DNS server is down (and any backup server is also down), it should still be possible to connect to the target host using the IP address.
8. What is the purpose of DHCP? When might it be a bad idea to use DHCP?The DHCP server can assign dynamic IP addresses to machines. On a small network that is cut off from the internet, all machines could have static addresses. Also, DHCP aids in scaling a network, so if the network is not expected to change in the future, it is unnecessary.
9. Why do we usually configure computers connected to the Internet with two different name server addresses?If one name server is down, the other can be used as a backup.
10. What is a "default gateway?" Why does your IP configuration need to include one?It is the router that connects the machines on a local network to the internet. All machines on the local network need to know the gateway address so they can communicate with machines outside the network (on the internet.)
11. Look at this IP address: 192.168.1.10It is a private, class C address. The standard subnet mask should be 255.255.255.0.
12. Run 'ipconfig /all' from your PC and answer these questions:The IP address is 192.168.1.11. It is a private, class C address. The address is assigned statically -- I have the router configured this way. The DNS server is 192.168.1.1. The default gateway is also 192.168.1.1.
13. Use the "traceroute" program (tracert at a Windows command prompt) to display the route that packets traverse between your PC and a server named www.unc.edu located at the University of North Carolina.
Tracing route to www.unc.edu [152.2.1.217]
over a maximum of 30 hops:
1 1 ms <1 ms 4 ms DD-WRT [192.168.1.1]
2 * * * Request timed out.
3 * 155 ms 161 ms 68.86.98.49
4 * 109 ms * te-9-3-ar01.burien.wa.seattle.comcast.net [68.86.96.66]
5 71 ms 83 ms 81 ms 12.118.106.5
6 150 ms 122 ms 109 ms 12.127.6.130
7 14 ms 49 ms 34 ms 12.127.6.57
8 47 ms 54 ms 55 ms so-3-2-0.gar1.Seattle1.Level3.net [4.68.127.109]
9 68 ms 122 ms 122 ms ae-32-52.ebr2.Seattle1.Level3.net [4.68.105.62]
10 68 ms 82 ms * ae-1-100.ebr2.Seattle1.Level3.net [4.69.132.18]
11 * 123 ms 111 ms ae-2.ebr2.Denver1.Level3.net [4.69.132.54]
12 133 ms * * ae-1-100.ebr2.Chicago1.Level3.net [4.69.132.42]
13 * * * Request timed out.
14 * 153 ms 136 ms ae-6-6.car2.Raleigh1.Level3.net [4.69.132.177]
15 155 ms 145 ms 151 ms ae-11-11.car1.Raleigh1.Level3.net [4.69.132.173]
16 142 ms 145 ms 127 ms MCNC.car1.Raleigh1.Level3.net [64.158.236.2]
17 163 ms 147 ms 131 ms rtp7600-gw-to-rtp1-gw-sec.ncren.net [128.109.70.82]
18 153 ms 163 ms 144 ms unc7600-gw-to-rtp7600-gw.ncren.net [128.109.70.34]
19 148 ms 149 ms 154 ms ciscokid.internet.unc.edu [128.109.36.253]
20 124 ms 116 ms 143 ms ciscokid.internet.unc.edu [128.109.36.253]
21 171 ms * * el-loco-v5.net.unc.edu [152.2.255.253]
22 * * * Request timed out.
23 * * * Request timed out.
24 * * * Request timed out.
25 * * * Request timed out.
26 * * * Request timed out.
27 * * * Request timed out.
28 * * * Request timed out.
29 * * * Request timed out.
30 * * * Request timed out.
It is a MAC address, the address of a network card.
15. This protocol in the TCP/IP protocol stack is responsible for determining how to get a packet to it's destination:c. IP
16. This protocol in the TCP/IP protocol stack is responsible for keeping the internet's lookup services running:b. DNS
Bonus (just for fun) questions:"0" -- the last octet identifies the host.
2. Given a source IP address of 10.1.2.3 with a SN Mask of 255.255.255.0 and a destination address of 10.1.3.4, are they on the same network? Why?No, they are not on the same network because routing on the same network would require the subnet mask to be 255.255.0.0 in that example.
3. Briefly explain what we mean when we say that TCP is a "connection-oriented, reliable" protocol?A permanent connection is maintained between the client and server machines, and both machines are notified when the connection is dropped. The reliability also comes from the handshaking that occurs.