Take the 2-minute tour ×
Server Fault is a question and answer site for professional system and network administrators. It's 100% free, no registration required.
  • I am in India
  • On ocassion I navigate to the portal of companies I'm affiliated to; these in the US, & Canada
  • As of today afternoon, I'm unable to navigate to the portal of some companies ... albeit the website is deployed and can be navigated to from people at third-party locations (outside US, and outside India).
  • Just for reference I executed a ping -t on one company site, and at the same time attempted to open the site in Chrome ** Chrome came up with a 500 error ** Ping returned a 'Request timed out' ** A colleague at third location reported he was able to both ping, and navigate to the site ** My subsequent tracert was got as far as border8.po2-bbnet2.bsn.pnap.net [63.251.128.77], and then returned a 'Request timed out'
  • I tried the same experiment on cbc.ca ** Result ** Chrome navigated to cbc.ca successfully ** Ping returned a 'Request timed out' ** Tracert got as far as rx0sh-cbc-radio-canada.mt.bigpipeinc.com [66.244.255.78], and then returned a 'Request timed out'.

I'm flummmoxed.

  • What could be the possible reasons that a browser can navigate to a site, when PING and TRACERT fail?
  • When my colleague is able to navigate to a site over the internet, why should the site return a 500 to me?
  • What can I do to work around this problem? My call to helpdesk went unanswered.
  • Have you ever encountered a similar problem?
share|improve this question
    
Thanks Josh & Joe; I didn't realize PING uses a different protocol altogether. –  Everyone Jul 13 '10 at 4:10
add comment

2 Answers 2

up vote 1 down vote accepted

Keep in mind that PING & Tracert do not use the same protocols that http does:

ICMP vs TCP

So, I could ping a webserver, and a firewall sitting in the middle of the connection disallows ICMP, but allows TCP Port 80 (Default http).

-Josh

share|improve this answer
add comment

You're mixing your tests and your test results up. That's the first problem.

While ping and tracert are good basic connectivity and path discovery tools, they're not the correct tools for diagnosing web site connectivity issues. A 500 error clearly means that you've gotten to the web site but that the server has some problem. The fact that your colleague can get to the web site tells you almost nothing. The web server may be having an intermittent problem or it may be geographically dispersed and you're hitting a cluster or server that's having problems while your colleague is hitting a cluster or server that isn't having problems.

As Josh stated a firewall may be configured to allow HTTP traffic to a particular host but it may not allow ICMP traffic to that same host, so the fact that your ping request times out tells you nothing about the status of that web server. The fact that your ping requests time out somewhere "in the middle" only means that those hosts don't respond to ICMP requests and again, tells you nothing about why you can't access the web site.

At the end of the day, the 500 error tells you all you need to know: you're getting to the web site but the server is having some problem. The best you can do is to communicate this information to the party that's responsible for the web site.

share|improve this answer
    
Thanks (+: The party that is responsible for the web-site unequivocally said the web-site is up, and running. My request didn't register on their log... so it's probably something along the route that is blocking the request from reaching them. Two follow-up questions here a) If some server along the path returned an error-code, wouldn't the request be redirected along a different path? b) IIRC VPN piggy-backs over HTTP; is this correct, or does VPN use a dedicated protocol that may be denied altogether? –  Everyone Jul 13 '10 at 4:15
1  
If you got a 500 error in your browser then you definitely got to the web site. en.wikipedia.org/wiki/HTTP_500#5xx_Server_Error. –  joeqwerty Jul 13 '10 at 12:07
add comment

Your Answer

 
discard

By posting your answer, you agree to the privacy policy and terms of service.

Not the answer you're looking for? Browse other questions tagged or ask your own question.