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Question about Ping RRS feed

  • Question

  • Why do I get different IP addresses when I ping www.microsoft.com & ping microsoft.com?

    With the 1st, I get 134.170.188.84 & when I key that into my browser address bar, I get this site:  http://134.170.188.84/en-ca/default.aspx  (which is Microsoft Canada's site).

    With the latter, I get 65.55.58.201 & in my browser, I get this site:  http://www.microsoft.com/en-ca/default.aspx  (same web page as the 1st).

    Thursday, January 16, 2014 8:05 PM

Answers

  • Simply because Microsoft, like many large companies, serve their websites from multiple IP addresses. There are different ways to achieve it, but it essentially load balances requests across multiple connections / locations. For instance in DNS you could have more than one DNS A record for www.microsoft.com, with each one pointing to a different IP address. Different results would be returned to each person doing a lookup.

    If you tried the same thing with Google, Yahoo or Amazon for instance you'd likely get the same result.

    • Proposed as answer by Danny van DamMVP, Editor Monday, January 20, 2014 10:50 AM
    • Marked as answer by me33 Monday, January 20, 2014 1:38 PM
    Thursday, January 16, 2014 8:20 PM
  • Without knowing how their websites are setup it's hard to be sure. With lots of web servers having multiple websites running on them you can't access them via IP. Every website must be identified by a unique combination of hostname, IP address and port number. If there is more than one website running then the IP address and port number will normally need to be the same, so the hostname has to change for each site. You can have one single website that will also respond on just the IP address and port (since that's still unique) but only one, and you have to specifically configure it to respond to that (this applies to both IIS and Apache).

    So on some single purpose websites the admin may have configured it to also respond to the IP address, but on others they might not have. Assuming you get different IP addresses returned for those two pings then my guess is that on the two servers those IP addresses point to, one is configured to accept IP and the other isn't.

    • Marked as answer by me33 Tuesday, January 21, 2014 2:20 AM
    Monday, January 20, 2014 5:11 PM

All replies

  • Simply because Microsoft, like many large companies, serve their websites from multiple IP addresses. There are different ways to achieve it, but it essentially load balances requests across multiple connections / locations. For instance in DNS you could have more than one DNS A record for www.microsoft.com, with each one pointing to a different IP address. Different results would be returned to each person doing a lookup.

    If you tried the same thing with Google, Yahoo or Amazon for instance you'd likely get the same result.

    • Proposed as answer by Danny van DamMVP, Editor Monday, January 20, 2014 10:50 AM
    • Marked as answer by me33 Monday, January 20, 2014 1:38 PM
    Thursday, January 16, 2014 8:20 PM
  • Hi, me33.

    I am way out of my league here (unqualified) but I suspect that the server handling microsoft.com is doing a simple redirect to www.microsoft.com

    Once redirected here, it is redirected to the Canadian version of the Microsoft site.

    I am only guessing; Microsoft will likely not share all of their route settings.

    You should try some of the cool online tools that can help you track some of this stuff.

    Here's three:
    http://ip-lookup.net/
    http://www.whatismyip.com/ip-tools/
    http://www.viewdns.info/

    Good luck!


    Best wishes, Davin Mickelson

    Thursday, January 16, 2014 9:09 PM
    Answerer
  • Thank you for your help!

    These sites are a great resource.

    Monday, January 20, 2014 1:39 PM
  • Thanks for the info. I had come across load balancing. Your answer makes sense.

    I do have a related question. For example, with cisco.com, my ping works & when I type the ip addr into my browser, it takes me to the site. But with :  ping www.cisco.com   - it works (I get the 'echo reply'), but when I enter the ip addr to browser, I get: 

    Invalid URL

    The requested URL "/", is invalid.
    Reference #9.cd2bf648.1390224922.a5549cd

    & the 'ping' echo reply gave:  pinging e144.dscb.akamaiedge.net

    Monday, January 20, 2014 1:44 PM
  • Without knowing how their websites are setup it's hard to be sure. With lots of web servers having multiple websites running on them you can't access them via IP. Every website must be identified by a unique combination of hostname, IP address and port number. If there is more than one website running then the IP address and port number will normally need to be the same, so the hostname has to change for each site. You can have one single website that will also respond on just the IP address and port (since that's still unique) but only one, and you have to specifically configure it to respond to that (this applies to both IIS and Apache).

    So on some single purpose websites the admin may have configured it to also respond to the IP address, but on others they might not have. Assuming you get different IP addresses returned for those two pings then my guess is that on the two servers those IP addresses point to, one is configured to accept IP and the other isn't.

    • Marked as answer by me33 Tuesday, January 21, 2014 2:20 AM
    Monday, January 20, 2014 5:11 PM