Troubleshooting Internet Connection Problems in Linux

tux_wifi2This is another short video I made on how to trouble shoot Internet connection problems in Linux. Because I have been experiencing constants Internet connection problems at home with my new provider “ACM,” that I’ve had to troubleshoot connection problems two, three, and even four times in a single day. So here Are the steps to use when ruling out connections problems with the Internet. In this case I’m using a Linux computer, but the steps are the same for Windows, just the commands are different.
Here are the steps:
when experiencing problem establishing connection with your browser to a especific website…
1- try a second or third website (different website rule out the option of one website being down, which is rare)
2- If after trying multiple websites, still unable to establish a connection, then check your ip configuration using ifconfig (Linux) and make sure you’re getting an ip address.

jorge@nixtop ~ $ ifconfig wlan0
wlan0     Link encap:Ethernet  HWaddr 88:9f:fa:79:0d:5c  
          inet addr:192.168.43.158  Bcast:192.168.43.255  Mask:255.255.255.0
          inet6 addr: fe80::8a9f:faff:fe79:d5c/64 Scope:Link
          UP BROADCAST RUNNING MULTICAST  MTU:1500  Metric:1
          RX packets:9424341 errors:0 dropped:1 overruns:0 frame:0
          TX packets:3834257 errors:0 dropped:0 overruns:0 carrier:0
          collisions:0 txqueuelen:1000 
          RX bytes:171961628 (171.9 MB)  TX bytes:727341281 (727.3 MB)

3- If your ip settings seem fine. Next try pinging the website in questions, for example

jorge@nixbox:~$ ping yahoo.com
PING yahoo.com (206.190.36.45) 56(84) bytes of data.
64 bytes from ir1.fp.vip.gq1.yahoo.com (206.190.36.45): icmp_seq=1 ttl=46 time=91.0 ms
64 bytes from ir1.fp.vip.gq1.yahoo.com (206.190.36.45): icmp_seq=2 ttl=46 time=91.8 ms
64 bytes from ir1.fp.vip.gq1.yahoo.com (206.190.36.45): icmp_seq=3 ttl=46 time=89.3 ms
64 bytes from ir1.fp.vip.gq1.yahoo.com (206.190.36.45): icmp_seq=4 ttl=46 time=91.0 ms

4- In this case, I’m getting a response from the website, but lets asume your ping responses fail, and you don’t get packets back from a website. You could try traceroute command
5- Use “traceroute” to trace every single router or hope between your computer and the destination website. If you get too many asterisk ‘*’ that’s indicative of routers timing out on your ping request; therefore, the problem might be somewhere between your computer and the destination website. Also, big numbers in ms, are a sign of routers experiencing bottlenecks; however, I’ve been able to connect to many websites even when I’m getting asterisk, and high numbers in my responses. But traceroute is a great troubleshooting tool when trying to pin-point where along the line is the connection problem.
Here’s an example output of traceroute command to yahoo.com

jorge@nixbox:~$ traceroute yahoo.com
traceroute to yahoo.com (206.190.36.45), 30 hops max, 60 byte packets
 1  192.168.200.1 (192.168.200.1)  0.503 ms  0.722 ms  1.336 ms
 2  10.1.8.1 (10.1.8.1)  11.296 ms  11.488 ms  11.551 ms
 3  172.16.4.1 (172.16.4.1)  13.425 ms  13.179 ms  13.480 ms
 4  xe-9-0-0-3998-sur01.hialeahwest.fl.pompano.comcast.net (107.1.248.161)  13.655 ms  13.570 ms  13.701 ms
 5  te-0-2-0-33-ar01.northdade.fl.pompano.comcast.net (162.151.123.105)  17.922 ms te-0-2-0-25-ar01.northdade.fl.pompano.comcast.net (69.139.181.169)  18.152 ms  18.223 ms
 6  be-20214-cr01.miami.fl.ibone.comcast.net (68.86.90.205)  21.231 ms  13.378 ms  26.047 ms
 7  ae12.edge2.Miami1.level3.net (4.68.127.205)  22.904 ms  22.627 ms  22.819 ms
 8  ae-24-52.car4.Seattle1.Level3.net (4.69.147.166)  96.022 ms  96.268 ms  96.335 ms
 9  ae-24-52.car4.Seattle1.Level3.net (4.69.147.166)  96.459 ms  96.517 ms  96.380 ms
10  YAHOO-INC.car4.Seattle1.Level3.net (4.79.106.26)  93.932 ms  93.851 ms  93.643 ms
11  ae-7.pat1.gqb.yahoo.com (216.115.96.45)  96.628 ms ae-7.pat2.gqb.yahoo.com (216.115.101.109)  91.850 ms ae-7.pat1.gqb.yahoo.com (216.115.96.45)  90.230 ms
12  ae-1.msr1.gq1.yahoo.com (66.196.67.5)  90.212 ms ae-0.msr2.gq1.yahoo.com (66.196.67.23)  89.880 ms  90.070 ms
13  xe-10-3-1.clr1-a-gdc.gq1.yahoo.com (67.195.1.191)  89.563 ms UNKNOWN-98-137-31-X.yahoo.com (98.137.31.143)  89.689 ms xe-11-2-1.clr1-a-gdc.gq1.yahoo.com (67.195.1.193)  89.783 ms
14  et-17-1.fab3-1-gdc.gq1.yahoo.com (98.137.31.172)  94.202 ms et-18-1.fab5-1-gdc.gq1.yahoo.com (67.195.1.235)  93.799 ms et-17-1.fab4-1-gdc.gq1.yahoo.com (98.137.31.176)  96.467 ms
15  po-10.bas1-7-prd.gq1.yahoo.com (206.190.32.15)  96.560 ms po-12.bas1-7-prd.gq1.yahoo.com (206.190.32.19)  96.331 ms po-10.bas2-7-prd.gq1.yahoo.com (206.190.32.31)  96.054 ms
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jorge@nixbox:~$

and I here’s the video for those who like to watch instead of reading the article.

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