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If I can generally reach web pages on the Internet but can't reach a specific one, how do I troubleshoot what the cause is as an end user?

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See also How do I diagnose when and why a website is down? on Web Applications – ChrisF Jan 16 '11 at 18:35
up vote 48 down vote accepted

Maybe the website is actually down.

Try visiting

down for everyone or just me

If it says "It's not just you" the website is likely having an outage and you should try to report it if possible -- or just wait.

Maybe it's a DNS problem.

See if the website DNS name (let's say it is resolves to an IP address. You can do this by starting a console or command prompt, and typing ping


Pinging [] with 32 bytes of data:
Reply from bytes=32 time=26ms TTL=244
Reply from bytes=32 time=27ms TTL=244
Reply from bytes=32 time=27ms TTL=244
Reply from bytes=32 time=39ms TTL=244

Ping statistics for
    Packets: Sent = 4, Received = 4, Lost = 0 (0% loss),
Approximate round trip times in milli-seconds:
    Minimum = 26ms, Maximum = 39ms, Average = 29ms

If you get an "unknown host" error this means there is likely a DNS problem. You can try seeing if it resolves against Google's DNS with nslookup


Non-authoritative answer:
Addresses:  2620:0:2d0:200::10

If it does resolve with that command then you probably want to contact your DNS provider (likely your ISP). If you want to run further DNS tests, try GRC's DNS Benchmark for Windows, or the services and

Maybe it's a browser problem.

If it does resolve in DNS, but you don't get ping replies it means they are either filtering pings or you can't reach that site. If you are getting replies you might have a browser or browser proxy issue. Try installing another web browser with all default settings and see if you get any different results.

Maybe it's a problem with your internet connection.

If it is resolving but you can't reach it try running tracert and see where they start timing out.

Tracing route to []
over a maximum of 30 hops:

  1    <1 ms    <1 ms    <1 ms 
  2    15 ms    26 ms    29 ms [x.x.x.x] 
  3    10 ms    25 ms     9 ms [] 
  4    12 ms    13 ms    14 ms [] 
  5    35 ms    15 ms    12 ms [] 
  6    15 ms    16 ms    18 ms [] 
  7    16 ms    18 ms    19 ms [] 
  8    27 ms    18 ms    33 ms [] 
  9    77 ms    29 ms   183 ms [] 
 10    28 ms    35 ms    35 ms [] 
 11    43 ms    27 ms    60 ms [] 
 12    23 ms    23 ms    28 ms [] 
 13    24 ms    23 ms    24 ms [] 

Trace complete.  

You can also try PingPlotter (Shareware; Free 30-day evaluation.) which will repeatedly run a traceroute and graph the results, so you can see if you have packet loss or bandwidth problems at any hop on the traceroute.

pingplotter to

Let this run for a while. If it is timing out after only an entry or two you probably want to contact your internet service provider. If it is timing out towards the end you should contact the webmaster of the site, if possible. Whoever you contact, include the output of the ping and traceroute commands.

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I fixed my problem to connect to chat.SE by switching DNS-es – Ivo Flipse Jan 17 '11 at 15:09
If it turns out that the website is actually down, you can let Firefox automatically keep retrying with TryAgain, an extension I actively develop with a colleague in my spare time. – Paul Lammertsma Mar 28 '11 at 10:42
Sorry that website seems to report sites being down that aren't. Looks like there are some bugs to work out still... – jjxtra Sep 1 '11 at 4:44
the Google Cache version of this page in case our network is unreachable. – Jeff Atwood Sep 23 '11 at 2:53

Something else to look for is a faulty router.

I recently had this situation with accessing any Stack Exchange site. It would time out, return connection errors and generally "lock me out" for 5 minutes at a time. Virtually all other sites were OK.

After lengthy chats with Stack Exchange staff (very helpful) and my ISP I narrowed it down to the router. Swapping it out has apparently cured the problem.

The problem here (I think) was that what ever the fault was on the router it couldn't cope with the relatively high volume of traffic I was generating when using Stack Exchange as a logged in user with multiple accounts and having a lot of them visible at any one time.

The fact that only one site (well one set of sites) was affected led me to believe that the problem lie elsewhere.

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These days one needs to consider IPv6. It's possible there is a problem with the IPv6 mechanism (DNS, routing, OS) but not IPv4 (or, less likely, vice versa). Both the ping and tracert commands as of Windows 7 take a -4 or -6 option to independently test IPv4 and the new IPv6.

This feels like a comment to the main answer, not another answer, but I don't have enough rep to comment. Or perhaps I should edit the Wiki, which would mean perhaps adding an example, since the answer is so professional looking. But I don't have enough rep for Wiki editing either.

Feel free to edit this as necessary.

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