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304# Lab 1
- Author: Jack Jiang
- email: z5129432@student.unsw.edu.au
## Exercise 1
### 1
IP: 216.58.196.132
Multi IP address is good for load balance reason. We can always connect to the server which is more close to us or has a lighter load.
### 2
Name: localhost
it is a reserved IP address. Computers use it to refer to themselves.
## Excercise 2
### 1. unreachable by PING and Web browser
this is because the host does not exist in DNS server.
- www.getfittest.com.au
- www.hola.hp
### 2. only unreachable by PING
Because the server has been configured(maybe by firewall) to not response to PING.
- http://www.kremlin.ru/
### 3. only unreachable by a Web browser
There is no web server running in this host.
- 8.8.8.8
## Exercise 3
### 1
```
traceroute to www.columbia.edu (128.59.105.24), 30 hops max, 60 byte packets
1 cserouter1-server.cse.unsw.EDU.AU (129.94.242.251) 0.097 ms 0.108 ms 0.100 ms
2 129.94.39.17 (129.94.39.17) 0.996 ms 1.023 ms 1.026 ms
3 ombudnex1-vl-3154.gw.unsw.edu.au (149.171.253.35) 1.679 ms libudnex1-vl-3154.gw.unsw.edu.au (149.171.253.34) 1.859 ms 1.823 ms
4 ombcr1-po-6.gw.unsw.edu.au (149.171.255.169) 1.257 ms libcr1-po-6.gw.unsw.edu.au (149.171.255.201) 1.238 ms ombcr1-po-5.gw.unsw.edu.au (149.171.255.197) 1.234 ms
5 unswbr1-te-1-9.gw.unsw.edu.au (149.171.255.101) 1.326 ms 1.291 ms 1.351 ms
6 138.44.5.0 (138.44.5.0) 1.497 ms 1.421 ms 1.409 ms
7 et-1-3-0.pe1.sxt.bkvl.nsw.aarnet.net.au (113.197.15.149) 2.433 ms 2.231 ms 2.312 ms
8 et-0-0-0.pe1.a.hnl.aarnet.net.au (113.197.15.99) 95.530 ms 95.553 ms 95.621 ms
9 et-2-1-0.bdr1.a.sea.aarnet.net.au (113.197.15.201) 146.475 ms 146.494 ms 146.462 ms
10 abilene-1-lo-jmb-706.sttlwa.pacificwave.net (207.231.240.8) 156.388 ms 156.260 ms 156.237 ms
11 et-4-0-0.4079.rtsw.miss2.net.internet2.edu (162.252.70.0) 157.358 ms 157.309 ms 157.291 ms
12 et-4-0-0.4079.rtsw.minn.net.internet2.edu (162.252.70.58) 180.453 ms 180.642 ms 180.410 ms
13 et-1-1-2.4079.rtsw.eqch.net.internet2.edu (162.252.70.106) 189.019 ms 188.779 ms 188.737 ms
14 ae-1.4079.rtsw.clev.net.internet2.edu (162.252.70.130) 196.880 ms 196.940 ms 196.948 ms
15 buf-9208-I2-CLEV.nysernet.net (199.109.11.33) 201.267 ms 201.195 ms 201.216 ms
16 syr-9208-buf-9208.nysernet.net (199.109.7.193) 205.201 ms 204.934 ms 205.467 ms
17 nyc-9208-syr-9208.nysernet.net (199.109.7.162) 210.246 ms 210.421 ms 210.410 ms
18 columbia.nyc-9208.nysernet.net (199.109.4.14) 210.225 ms 210.267 ms 228.239 ms
19 cc-core-1-x-nyser32-gw-1.net.columbia.edu (128.59.255.5) 210.739 ms 210.682 ms 210.702 ms
20 cc-conc-1-x-cc-core-1.net.columbia.edu (128.59.255.210) 210.831 ms 210.822 ms 210.867 ms
21 columbiauniversity.org (128.59.105.24) 210.695 ms 210.702 ms 210.712 ms
```
There are 21 routers in between. Five of them are part of UNSW network.
Between router 113.197.15.149 and 113.197.15.99, the package crosses the Pacific Ocean because the latency is the largest.
### 2
```
traceroute to www.ucla.edu (164.67.228.152), 30 hops max, 60 byte packets
1 cserouter1-server.cse.unsw.EDU.AU (129.94.242.251) 0.206 ms 0.196 ms 0.185 ms
2 129.94.39.17 (129.94.39.17) 1.331 ms 1.325 ms 1.309 ms
3 ombudnex1-vl-3154.gw.unsw.edu.au (149.171.253.35) 2.779 ms libudnex1-vl-3154.gw.unsw.edu.au (149.171.253.34) 2.618 ms ombudnex1-vl-3154.gw.unsw.edu.au (149.171.253.35) 2.765 ms
4 ombcr1-po-5.gw.unsw.edu.au (149.171.255.197) 1.493 ms 1.477 ms libcr1-po-5.gw.unsw.edu.au (149.171.255.165) 1.337 ms
5 unswbr1-te-1-9.gw.unsw.edu.au (149.171.255.101) 2.476 ms 2.556 ms 2.549 ms
6 138.44.5.0 (138.44.5.0) 2.885 ms 4.167 ms 4.135 ms
7 et-1-3-0.pe1.sxt.bkvl.nsw.aarnet.net.au (113.197.15.149) 4.120 ms 3.635 ms 4.929 ms
8 et-0-0-0.pe1.a.hnl.aarnet.net.au (113.197.15.99) 96.573 ms 96.484 ms 96.576 ms
9 et-2-1-0.bdr1.a.sea.aarnet.net.au (113.197.15.201) 147.637 ms 146.978 ms 146.835 ms
10 cenichpr-1-is-jmb-778.snvaca.pacificwave.net (207.231.245.129) 163.609 ms 163.678 ms 163.427 ms
11 hpr-lax-hpr3--svl-hpr3-100ge.cenic.net (137.164.25.73) 171.176 ms 172.392 ms 172.185 ms
12 * * *
13 bd11f1.anderson--cr00f2.csb1.ucla.net (169.232.4.4) 172.543 ms bd11f1.anderson--cr001.anderson.ucla.net (169.232.4.6) 171.224 ms bd11f1.anderson--cr00f2.csb1.ucla.net (169.232.4.4) 171.651 ms
14 cr00f1.anderson--dr00f2.csb1.ucla.net (169.232.4.55) 204.726 ms cr00f2.csb1--dr00f2.csb1.ucla.net (169.232.4.53) 171.440 ms 171.406 ms
15 * * *
16 * * *
17 * * *
18 * * *
19 * * *
20 * * *
21 * * *
22 * * *
23 * * *
24 * * *
25 * * *
26 * * *
27 * * *
28 * * *
29 * * *
30 * * *
```
```
traceroute to www.u-tokyo.ac.jp (210.152.243.234), 30 hops max, 60 byte packets
1 cserouter1-server.cse.unsw.EDU.AU (129.94.242.251) 0.105 ms 0.126 ms 0.103 ms
2 129.94.39.17 (129.94.39.17) 0.998 ms 1.015 ms 0.979 ms
3 libudnex1-vl-3154.gw.unsw.edu.au (149.171.253.34) 1.922 ms 1.926 ms 1.440 ms
4 ombcr1-po-5.gw.unsw.edu.au (149.171.255.197) 1.170 ms libcr1-po-5.gw.unsw.edu.au (149.171.255.165) 1.251 ms 1.257 ms
5 unswbr1-te-1-9.gw.unsw.edu.au (149.171.255.101) 1.271 ms 1.289 ms 1.328 ms
6 138.44.5.0 (138.44.5.0) 1.403 ms 1.391 ms 1.370 ms
7 et-0-3-0.pe1.bkvl.nsw.aarnet.net.au (113.197.15.147) 1.878 ms 2.014 ms 2.040 ms
8 ge-4_0_0.bb1.a.pao.aarnet.net.au (202.158.194.177) 156.320 ms 156.247 ms 156.294 ms
9 paloalto0.iij.net (198.32.176.24) 158.052 ms 158.116 ms 157.974 ms
10 osk004bb01.IIJ.Net (58.138.88.189) 271.360 ms osk004bb00.IIJ.Net (58.138.88.185) 288.765 ms osk004bb01.IIJ.Net (58.138.88.189) 271.258 ms
11 osk004ix51.IIJ.Net (58.138.106.126) 279.854 ms 279.852 ms 279.845 ms
12 210.130.135.130 (210.130.135.130) 280.017 ms 279.989 ms 271.103 ms
13 124.83.228.78 (124.83.228.78) 288.575 ms 288.563 ms 279.793 ms
14 124.83.252.250 (124.83.252.250) 286.325 ms 277.582 ms 277.519 ms
15 158.205.134.26 (158.205.134.26) 277.450 ms 286.383 ms 307.062 ms
16 * * *
17 * * *
18 * * *
19 * * *
20 * * *
21 * * *
22 * * *
23 * * *
24 * * *
25 * * *
26 * * *
27 * * *
28 * * *
29 * * *
30 * * *
```
It diverge at router et-0-3-0.pe1.bkvl.nsw.aarnet.net.au (113.197.15.147).
No. There is 12050 km between localhost and www.ucla.edu, while there is only 7891 km between localhost to www.u-tokyo.ac.jp. However, both of them has 30 routers.
### 3
speedtest to 129.94.208.147
```
traceroute to 129.94.208.147 (129.94.208.147), 30 hops max, 60 byte packets
1 ge2-8.r01.sin01.ne.com.sg (202.150.221.169) 0.143 ms 0.141 ms 0.139 ms
2 10.11.33.38 (10.11.33.38) 32.931 ms 32.936 ms 32.934 ms
3 hutchcity3-10g.hkix.net (123.255.90.140) 53.147 ms 53.150 ms 53.218 ms
4 d1-42-238-143-118-on-nets.com (118.143.238.42) 44.547 ms 48.850 ms 218.189.5.42 (218.189.5.42) 48.772 ms
5 d1-6-224-143-118-on-nets.com (118.143.224.6) 195.212 ms 196.219 ms d1-26-224-143-118-on-nets.com (118.143.224.26) 203.632 ms
6 aarnet.as7575.any2ix.coresite.com (206.72.210.64) 187.256 ms 195.124 ms 189.783 ms
7 xe-0-0-3.pe1.tkpa.akl.aarnet.net.au (202.158.194.172) 318.453 ms 313.212 ms 304.088 ms
8 et-0-1-0.200.pe1.wnpa.akl.aarnet.net.au (113.197.15.68) 314.497 ms 312.415 ms 312.249 ms
9 xe-1-2-1.pe1.msct.nsw.aarnet.net.au (113.197.15.66) 336.606 ms 339.582 ms 331.214 ms
10 et-8-1-0.pe1.brwy.nsw.aarnet.net.au (113.197.15.152) 348.452 ms 347.925 ms 352.990 ms
11 138.44.5.1 (138.44.5.1) 334.095 ms 335.242 ms 342.476 ms
12 libcr1-te-1-5.gw.unsw.edu.au (149.171.255.102) 323.924 ms 333.593 ms 334.018 ms
13 libudnex1-po-1.gw.unsw.edu.au (149.171.255.166) 342.098 ms ombudnex1-po-1.gw.unsw.edu.au (149.171.255.202) 326.927 ms 337.586 ms
14 ufw1-ae-1-3154.gw.unsw.edu.au (149.171.253.36) 344.395 ms 335.511 ms 335.518 ms
15 129.94.39.23 (129.94.39.23) 337.211 ms 336.197 ms 336.894 ms
16 * * *
17 * * *
18 * * *
19 * * *
20 * * *
21 * * *
22 * * *
23 * * *
24 * * *
25 * * *
26 * * *
27 * * *
28 * * *
29 * * *
30 * * *
```
129.94.208.147 to speedtest
```
traceroute to www.speedtest.com.sg (202.150.221.170), 30 hops max, 60 byte packets
1 cserouter1-trusted.cse.unsw.EDU.AU (129.94.208.251) 0.124 ms 0.133 ms 0.107 ms
2 129.94.39.17 (129.94.39.17) 1.077 ms 1.065 ms 1.010 ms
3 ombudnex1-vl-3154.gw.unsw.edu.au (149.171.253.35) 1.850 ms libudnex1-vl-3154.gw.unsw.edu.au (149.171.253.34) 1.438 ms ombudnex1-vl-3154.gw.unsw.edu.au (149.171.253.35) 1.810 ms
4 ombcr1-po-5.gw.unsw.edu.au (149.171.255.197) 1.254 ms ombcr1-po-6.gw.unsw.edu.au (149.171.255.169) 1.233 ms libcr1-po-6.gw.unsw.edu.au (149.171.255.201) 1.254 ms
5 unswbr1-te-2-13.gw.unsw.edu.au (149.171.255.105) 1.295 ms 1.275 ms 1.307 ms
6 138.44.5.0 (138.44.5.0) 1.506 ms 1.423 ms 1.480 ms
7 et-0-3-0.pe1.alxd.nsw.aarnet.net.au (113.197.15.153) 1.786 ms 1.968 ms 1.908 ms
8 xe-0-0-3.pe1.wnpa.akl.aarnet.net.au (113.197.15.67) 24.560 ms 24.649 ms 24.565 ms
9 et-0-1-0.200.pe1.tkpa.akl.aarnet.net.au (113.197.15.69) 24.759 ms 24.751 ms 24.774 ms
10 xe-0-2-6.bdr1.a.lax.aarnet.net.au (202.158.194.173) 148.382 ms 148.363 ms 148.297 ms
11 singtel.as7473.any2ix.coresite.com (206.72.210.63) 321.688 ms 321.702 ms 321.684 ms
12 203.208.154.45 (203.208.154.45) 358.726 ms 203.208.172.173 (203.208.172.173) 336.353 ms 336.340 ms
13 203.208.182.77 (203.208.182.77) 341.645 ms 203.208.177.110 (203.208.177.110) 353.230 ms 355.650 ms
14 202-150-221-170.rev.ne.com.sg (202.150.221.170) 357.358 ms 357.452 ms 355.681 ms
```
telstra to 129.94.208.147
```
1 gigabitethernet3-3.exi2.melbourne.telstra.net (203.50.77.53) 0.353 ms 0.203 ms 0.242 ms
2 bundle-ether3-100.win-core10.melbourne.telstra.net (203.50.80.129) 1.738 ms 1.477 ms 2.239 ms
3 bundle-ether12.ken-core10.sydney.telstra.net (203.50.11.122) 13.486 ms 12.097 ms 12.736 ms
4 bundle-ether1.ken-edge901.sydney.telstra.net (203.50.11.95) 11.983 ms 11.844 ms 11.860 ms
5 aarnet6.lnk.telstra.net (139.130.0.78) 11.607 ms 11.600 ms 11.610 ms
6 ge-6-0-0.bb1.a.syd.aarnet.net.au (202.158.202.17) 11.858 ms 11.724 ms 11.860 ms
7 ae9.pe2.brwy.nsw.aarnet.net.au (113.197.15.56) 12.112 ms 12.098 ms 12.110 ms
8 et-3-1-0.pe1.brwy.nsw.aarnet.net.au (113.197.15.146) 12.360 ms 12.472 ms 12.360 ms
9 138.44.5.1 (138.44.5.1) 12.609 ms 12.726 ms 12.613 ms
10 ombcr1-te-1-5.gw.unsw.edu.au (149.171.255.106) 12.609 ms 12.599 ms 12.612 ms
11 ombudnex1-po-2.gw.unsw.edu.au (149.171.255.170) 12.859 ms 12.848 ms 12.859 ms
12 ufw1-ae-1-3154.gw.unsw.edu.au (149.171.253.36) 13.235 ms 13.223 ms 13.235 ms
13 129.94.39.23 (129.94.39.23) 13.358 ms 13.352 ms 13.482 ms
```
129.94.208.147 to telstra
```
traceroute to www.telstra.net (203.50.5.178), 30 hops max, 60 byte packets
1 cserouter1-trusted.cse.unsw.EDU.AU (129.94.208.251) 0.185 ms 0.156 ms 0.132 ms
2 129.94.39.17 (129.94.39.17) 1.153 ms 1.105 ms 1.107 ms
3 ombudnex1-vl-3154.gw.unsw.edu.au (149.171.253.35) 8.825 ms 8.825 ms 8.793 ms
4 ombcr1-po-6.gw.unsw.edu.au (149.171.255.169) 1.381 ms libcr1-po-6.gw.unsw.edu.au (149.171.255.201) 1.495 ms 1.467 ms
5 unswbr1-te-1-9.gw.unsw.edu.au (149.171.255.101) 1.317 ms unswbr1-te-2-13.gw.unsw.edu.au (149.171.255.105) 1.297 ms 1.303 ms
6 138.44.5.0 (138.44.5.0) 1.657 ms 1.533 ms 1.424 ms
7 et-0-3-0.pe1.bkvl.nsw.aarnet.net.au (113.197.15.147) 1.814 ms 1.803 ms 1.748 ms
8 ae9.bb1.a.syd.aarnet.net.au (113.197.15.57) 2.064 ms 2.124 ms 2.195 ms
9 gigabitethernet1-1.pe1.b.syd.aarnet.net.au (202.158.202.18) 102.862 ms 102.869 ms 102.850 ms
10 gigabitethernet3-11.ken37.sydney.telstra.net (139.130.0.77) 2.965 ms 3.164 ms 3.165 ms
11 bundle-ether13.ken-core10.sydney.telstra.net (203.50.11.94) 4.405 ms 4.382 ms 5.034 ms
12 bundle-ether10.win-core10.melbourne.telstra.net (203.50.11.123) 15.869 ms 15.471 ms 15.387 ms
13 gigabitethernet5-0.exi-service2.melbourne.telstra.net (203.50.80.132) 13.936 ms 13.880 ms 13.782 ms
14 * * *
15 * * *
16 * * *
17 * * *
18 * * *
19 * * *
20 * * *
21 * * *
22 * * *
23 * * *
24 * * *
25 * * *
26 * * *
27 * * *
28 * * *
29 * * *
30 * * *
```
IP of speedtest is 202.150.221.170; IP of telstra is 203.50.5.178
No, the reverse path does NOT go through the same routers as the forward path.
No, the IP is not the same as common routers between the forward and the reverse path, because when routing, it will pick the nearest IP, and the nearest IP may not be the same between the forward and the backward path.
## Excercise 4
www.nus.edu.sg_delay.png
www.nus.edu.sg_scatter.png
www.tu-berlin.de_delay.png
www.tu-berlin.de_scatter.png
www.uq.edu.au_delay.png
www.uq.edu.au_scatter.png
### 1
- UNSW to www.nus.edu.sg (137.132.21.27) is 6310km
- UNSW to www.tu-berlin.de (130.149.7.201) is 16100km
- UNSW to www.uq.edu.au (130.102.131.123) is 730.3km
1. The speed is less than light because it may be in some medium
2. The actual distance may be longer than a straight line distance
### 2
it varies over time because of the congestion status which may affect the queue delay
### 3
- propagation delay is equal to d/S, which does NOT depend on the packet size.
- transmission delay is equal to L/R, which is proportional to the packet size
- processing delay depend on the packet size because larger size packet needs more processing time (e.g. calculate checksum).
- queuing delay does NOT depend on the packet size, it depends on buffer size.