Used to determine if you can reach a server
A Successful Ping :
ping 8.8.8.8 PING 8.8.8.8 (8.8.8.8): 56 data bytes 64 bytes from 8.8.8.8: icmp_seq=0 ttl=57 time=12.892 ms 64 bytes from 8.8.8.8: icmp_seq=1 ttl=57 time=12.521 ms
An unsuccessful ping
ping 8.8.8.9 PING 8.8.8.9 (8.8.8.9): 56 data bytes Request timeout for icmp_seq 0 Request timeout for icmp_seq 1
Can be entered in CMD or Linux Terminal ping <URL OR IP Address>
traceroute used to track route packets take to network host
Successful Traceroute
traceroute google.ie
traceroute to google.ie (216.58.194.195), 64 hops max, 52 byte packets
1 10.5.5.1 (10.5.5.1) 1.181 ms 0.952 ms 0.903 ms
2 d-clon-asr1k.magnet.ie (85.91.0.121) 11.605 ms 14.259 ms 14.413 ms
3 d-clon-core1a.magnet.ie (85.91.0.116) 12.046 ms 15.637 ms 13.594 ms
4 d-rte-core1a.magnet.ie (85.91.3.2) 12.648 ms 12.918 ms 10.985 ms
5 85.91.3.181 (85.91.3.181) 14.005 ms 16.541 ms 14.225 ms
6 74.125.50.253 (74.125.50.253) 12.336 ms 11.716 ms 12.230 ms
7 209.85.252.198 (209.85.252.198) 11.406 ms 12.064 ms 12.008 ms
8 216.239.42.241 (216.239.42.241) 21.312 ms 21.681 ms 21.833 ms
9 108.170.236.33 (108.170.236.33) 98.285 ms
216.239.42.223 (216.239.42.223) 98.982 ms 96.635 ms
10 209.85.253.248 (209.85.253.248) 111.174 ms 116.713 ms 115.174 ms
11 72.14.232.70 (72.14.232.70) 120.937 ms 119.599 ms 119.836 ms
12 209.85.251.139 (209.85.251.139) 130.766 ms 134.095 ms 130.749 ms
13 216.239.49.34 (216.239.49.34) 156.740 ms 156.260 ms 155.978 ms
14 209.85.249.62 (209.85.249.62) 156.036 ms
209.85.246.39 (209.85.246.39) 156.995 ms 157.330 ms
15 108.170.242.225 (108.170.242.225) 159.291 ms
108.170.243.1 (108.170.243.1) 158.126 ms 154.873 ms
16 108.170.237.105 (108.170.237.105) 155.194 ms 155.200 ms 155.623 ms
17 sfo03s01-in-f3.1e100.net (216.58.194.195) 160.806 ms 164.841 ms 170.866 ms
Unsuccessful Traceroute
traceroute 8.8.8.9
traceroute to 8.8.8.9 (8.8.8.9), 64 hops max, 52 byte packets
1 10.5.5.1 (10.5.5.1) 1.075 ms 0.797 ms 0.782 ms
2 d-clon-asr1k.magnet.ie (85.91.0.121) 17.426 ms 19.110 ms 17.468 ms
3 d-clon-core1a.magnet.ie (85.91.0.116) 14.062 ms 15.015 ms 15.636 ms
4 d-rte-core1a.magnet.ie (85.91.3.2) 17.509 ms 16.887 ms 13.270 ms
5 85.91.3.181 (85.91.3.181) 13.070 ms 17.265 ms 74.194 ms
6 74.125.50.253 (74.125.50.253) 11.457 ms 12.806 ms 13.088 ms
7 209.85.252.196 (209.85.252.196) 17.259 ms 14.733 ms
209.85.252.198 (209.85.252.198) 18.304 ms
8 72.14.236.7 (72.14.236.7) 26.750 ms
216.239.50.243 (216.239.50.243) 29.860 ms
209.85.248.57 (209.85.248.57) 24.639 ms
9 209.85.244.47 (209.85.244.47) 30.573 ms
209.85.246.231 (209.85.246.231) 47.177 ms
209.85.253.108 (209.85.253.108) 28.237 ms
10 108.170.237.131 (108.170.237.131) 26.928 ms
108.170.232.7 (108.170.232.7) 28.285 ms
72.14.238.201 (72.14.238.201) 29.297 ms
11 * * *
12 * * *
Note recurring * * * means that it cannot reach the server
Can be entered in Linux Terminal
traceroute <IP or URL>
A lot can be done with TCP Dump such as monitoring traffic on a specific ethernet port or wifi. A specific port on that device such as port 8080 can be monitored or the traffic from a certain ip address can be monitored.
The data from tcpdump can be sent to a file but please visit http://www.tecmint.com/12-tcpdump-commands-a-network-sniffer-tool/
For a list of commonly used tcpdump commands.
Note as TCP may be listening on reserved ports you may need to run it as sudo