internet - How do I diagnose not being able to reach a specific website as an end user?
2014-04
Kyle Brandt
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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ChrisF
Maybe the website is actually down.
Try visiting http://downforeveryoneorjustme.com.
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 example.com) resolves to an IP address. You can do this by starting a console or command prompt, and typing ping example.com
C:\Users\Jeff>ping example.com
Pinging example.com [192.0.32.10] with 32 bytes of data:
Reply from 192.0.32.10: bytes=32 time=26ms TTL=244
Reply from 192.0.32.10: bytes=32 time=27ms TTL=244
Reply from 192.0.32.10: bytes=32 time=27ms TTL=244
Reply from 192.0.32.10: bytes=32 time=39ms TTL=244
Ping statistics for 192.0.32.10:
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 stackoverflow.com 8.8.8.8.
C:\Users\Jeff>nslookup example.com 8.8.8.8
Server: google-public-dns-a.google.com
Address: 8.8.8.8
Non-authoritative answer:
Name: example.com
Addresses: 2620:0:2d0:200::10
192.0.32.10
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 just-ping.com and whatsmydns.net.
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 example.com and see where they start timing out.
Tracing route to example.com [192.0.32.10]
over a maximum of 30 hops:
1 <1 ms <1 ms <1 ms 192.168.1.1
2 15 ms 26 ms 29 ms c-x-x-x-x.hsd1.ca.comcast.net [x.x.x.x]
3 10 ms 25 ms 9 ms te-5-4-ur04.pinole.ca.sfba.comcast.net [68.86.248.169]
4 12 ms 13 ms 14 ms te-0-6-0-0-ar01.oakland.ca.sfba.comcast.net [68.85.154.86]
5 35 ms 15 ms 12 ms pos-0-3-0-0-cr01.sacramento.ca.ibone.comcast.net [68.86.90.129]
6 15 ms 16 ms 18 ms pos-0-9-0-0-cr01.sanjose.ca.ibone.comcast.net [68.86.85.181]
7 16 ms 18 ms 19 ms xe-11-1-0.edge1.SanJose1.Level3.net [4.79.43.133]
8 27 ms 18 ms 33 ms vlan69.csw1.SanJose1.Level3.net [4.68.18.62]
9 77 ms 29 ms 183 ms ae-63-63.ebr3.SanJose1.Level3.net [4.69.134.225]
10 28 ms 35 ms 35 ms ae-2-2.ebr3.LosAngeles1.Level3.net [4.69.132.10]
11 43 ms 27 ms 60 ms ae-31-80.car1.LosAngeles1.Level3.net [4.69.144.131]
12 23 ms 23 ms 28 ms INTERNET-CO.car1.LosAngeles1.Level3.net [4.71.140.222]
13 24 ms 23 ms 24 ms www.example.com [192.0.32.10]
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.
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.
David Z
For about a week I've been having trouble accessing a website I frequently visit from my laptop in my apartment. (The domain is http://www.irishgaelictranslator.com if it matters.) Symptoms are as follows:
- Whenever I try to access the site normally (i.e. in a browser) the connection times out.
- Trying to resolve the site name on DNS using
dig +showsearch +trace www.irishgaelictranslator.comends with the message "connection timed out; no servers could be reached".digis able to retrieve the NS records for the domain, which specify the nameserversns1.irish-sayings.com.(207.58.181.154) andns2.irish-sayings.com.(207.58.181.155). It times out trying to connect to either of those servers. - The IP address for
www.irishgaelictranslator.comis 207.58.181.154, and attempts to ping that IP address are unsuccessful. The connection times out. - When running
traceroutethe trace reaches up tosc-smv1461.servint.net (209.50.237.172)(step 21) with no problems or delays, and then I get just* * *after that.
So far it just sounds like the server is down. But here's the weird thing: I have no problems accessing http://www.irishgaelictranslator.com from any other computer. I also have no problems accessing any other websites from my laptop. As far as I can tell, it's only the one particular combination of my laptop in my apartment and this one website that is causing problems. (I haven't tried taking my laptop elsewhere, but that's probably next on my list)
What sort of diagnostics can/should I run to try to figure out what's going on here? As mentioned, I've already tried ping, traceroute, and dig, and I've also fired up Wireshark during all three of these to see if it showed anything useful, but I haven't seen anything that signals a problem to me. (I'm not the greatest networking expert, I could be missing something) Is there anything else to do?
As the tags suggest, I primarily run Linux, but I do have Windows available to test with as well. (I have the same connectivity problems to the website when I'm running Windows, so it's not an operating-system-dependent problem.)
EDIT: The problem turned out to be that my IP address was blacklisted by the server's firewall. No idea how it got on the blacklist, but the site admin removed it and the connection works now. Anyway, even though my specific problem has been resolved, I'm still interested in any more suggestions as to tests I could have done to gather useful information.
William Hilsum
Have you tried another computer in your house on the same internet connection (1), or your laptop on a different internet connection (2)?
I had a friend with the same issue and when he tried (1), he had the same problem and could not work out why when he took his laptop to my house, he could access a website.
I emailed the site administrator, and it turns out that he had blocked the entire IP range because someone was giving him problems.
You never know, it may be worth a try!
It could explain why DNS can resolve, but no connectivity. (just tried pinging from here and it worked)
If you have tried (2), ignore the above and I will give it another think!
Until then, if you need it urgently, try using a proxy server and see if you have any luck,
edit -- as well as that, it could be your ISP blocking it. If they have any forums, you may want to take a look. I know that I was trying to diagnose a similar problem for a good 2 days for a client and it turned out that the site was incorrectly placed on the IWF list (good in principal, rubbish in implementation), and the ISP was simply dropping all packets to the site without any warning. It got removed after I kicked up a fuss, but got no apology or explanation.
nik
Firstly, the server is reachable from where I try.
$ ping 207.58.181.154 PING 207.58.181.154 (207.58.181.154): 56 data bytes 64 bytes from 207.58.181.154: icmp_seq=0 ttl=52 time=312 ms 64 bytes from 207.58.181.154: icmp_seq=1 ttl=52 time=296 ms 64 bytes from 207.58.181.154: icmp_seq=2 ttl=52 time=296 ms 64 bytes from 207.58.181.154: icmp_seq=3 ttl=52 time=296 ms 64 bytes from 207.58.181.154: icmp_seq=4 ttl=52 time=296 ms ----207.58.181.154 PING Statistics---- 5 packets transmitted, 5 packets received, 0.0% packet loss round-trip (ms) min/avg/max/med = 296/299/312/296
Was able to complete a traceroute in 9 hops.
[snip] 8 296 ms 296 ms 296 ms sc-smv1461.servint.net [209.50.237.172] 9 296 ms 296 ms 296 ms vps.irish-sayings.com [207.58.181.154]
The site seems to have recently (July 29) changed from 69.57.140.72 to 207.58.181.154.
- Can you try the following lookup?
dig @208.67.222.222 -x 207.58.181.154
- Since changing the OS on the same laptop reproduces the problem,
It is more likely to be on the network path beyond it.
Some curious questions:- Does your external IP address change across the Linux and Winodws boot?
- Do the other machines you use from the same point as your laptop have different IP addresses?
- Do you have broadband/dialup connection that gives you a different IP address each time you login?