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Gargoyle
http://ga.rgoyle.com
 
Join Date: May 2004
Location: In your dock hiding behind your finder icon!
 
2005-10-18, 19:20

How do I test my network connection?

This is not specifically a common question, but is the starting point to finding the problem and solution for a lot of network related issues. It consists of 3 basic steps which I would normally do in terminal, but for the sake of this FAQ I'm going to use the GUI tools.

Step 1 - Testing your core network software
  • Launch "Network Utility" from Applications/Utilities.
  • Select the "Ping" tab from the top.
  • In the first text box (Network Address) enter "127.0.0.1"
  • Make sure that the "Send only 10 pings" option is chosen.
  • Click the "Ping" button to the right.
You should see results like this...
Code:
Ping has started ... PING 127.0.0.1 (127.0.0.1): 56 data bytes 64 bytes from 127.0.0.1: icmp_seq=0 ttl=64 time=0.101 ms 64 bytes from 127.0.0.1: icmp_seq=1 ttl=64 time=0.098 ms 64 bytes from 127.0.0.1: icmp_seq=2 ttl=64 time=0.092 ms 64 bytes from 127.0.0.1: icmp_seq=3 ttl=64 time=0.094 ms 64 bytes from 127.0.0.1: icmp_seq=4 ttl=64 time=0.089 ms 64 bytes from 127.0.0.1: icmp_seq=5 ttl=64 time=0.094 ms 64 bytes from 127.0.0.1: icmp_seq=6 ttl=64 time=0.091 ms 64 bytes from 127.0.0.1: icmp_seq=7 ttl=64 time=0.092 ms 64 bytes from 127.0.0.1: icmp_seq=8 ttl=64 time=0.117 ms 64 bytes from 127.0.0.1: icmp_seq=9 ttl=64 time=0.090 ms --- 127.0.0.1 ping statistics --- 10 packets transmitted, 10 packets received, 0% packet loss round-trip min/avg/max/stddev = 0.089/0.096/0.117/0.008 ms
This test uses a special IP address to test your TCP/IP software. If you get errors at this point then you need to resolve them before you go any further.

Step 2 - Testing your cable / wireless connection
90% of the time, your computer will be on a local area network (LAN) and there will be some sort of router between you and the rest of the internet. For the rest of this test I am going to assume your computer is connected to an ADSL router and that the router is set to give out network information using DHCP.
  • Open "System Preferences" and choose "Network".
  • From the "Show" drop-down menu, select "Network Status".
  • Select the connection you're testing and choose "Configure".
  • Choose the TCP/IP tab from the top.
  • Verify that "Using DHCP" is selected from the "Configure IPv4" option. If not, select it and click "Apply Now" from the bottom right corner.
  • Make a note of the number shown next to "Router".
  • Return to the status screen by choosing "Network Status" from the "Show" drop-down menu.
  • The coloured dot next to the connection you are testing should be green.
If the dot is not green then you have a problem with your physical connection or router/modem settings. If the dot is green, continue...
  • Switch back to the "Network Utility" and the "Ping" tab.
  • Replace the 127.0.0.1 address with the number you took note of from the previous section.
  • Click "Ping".
You should see almost identical results to the first test. If you get errors here then your computer cannot talk to your router. Recheck all your settings using the instructions that came with the router.

Step 3 - Testing the 'net
While still in the "Network Utility" programs "Ping" tab, replace your "Router" IP address from the previous step with "www.google.com" and click "Ping". Once again you should see the same type of results from the previous step. Alternatively, you could just try to access a website. However, you must make sure you do not load a cached page. The easiest way to do this is to go to google and search for a random string.

If you get an error that states "Unable to resolve" or "Unknown host" or if the Ping appears to do nothing for a long period, then you have an internet connection problem.

If you have passed all these tests and still can't connect to XYZ...
Then ether the fault is with the destination server, or your firewall settings. Ask in Genius Bar, and give as much information as possible, including that you have completed the "Network Test" in the FAQ's.

Hope this helps!

OK, I have given up keeping this sig up to date. Lets just say I'm the guy that installs every latest version as soon as its available!
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