Previous 1 2 Next 21 Replies Latest reply: Jun 20, 2013 10:39 AM by bug00 Go to original post
  • bug00 Level 1 (45 points)

    Hi Linc.  Thanks again for the further instructions.


    I stumbled onto something yesterday that is fascinating.  My husband left for the evening, and all of a sudden my ability to go to those two sites became significantly faster.  As fast as his MBP's load times normally are.  I experimented throughout the day today to make sure that the problem can be consistantly replicated.  It can.


    This is a little hard to explain in writing, so I hope you can hang with me.  First, as background:  both sites I experience a slowdown with are self-administered Wordpress-based sites hosted on the same GoDaddy server. One is mine, one is his.  What I eventually discovered is that whenever his laptop has a browser window open in which he is logged in as the administrator of HIS Wordpress site, then my browser speed is completely bogged down in trying to load MINE (even just as a viewer...not even trying to log in). Keep in mind that each of these two sites have completely DIFFERENT domain names.  But again...I do know that they are hosted on the same server. 


    In a nutshell:  if he is logged into his site on his computer, then my speed reduces drastically loading the other (my own) site on my computer. Every. Single. Time.


    The minute I close his browser window on his MPB, then my MPB's speed to load my site's url is is returned to normal.

    I initially thought maybe it was some kind of "first in" gets priority...perhaps because our wireless network is set up to share an IP address using DHCP.  BUT, when I reverse the procedure and log into one of the sites first on my MPB, his laptop still loads the pages with full speed.  It is only when *HIS* MBP logs into one of the pages first, that my MBP load times increase exponentially.


    Obviously, this does give me a non-elegant workaround (make him log off, if I need to look at my site)...but it is still the biggest mystery.  I just have no idea why it would behave in this way.  It would seem that in a corporate environment that people on different computers are concurently hitting the same sites all throughout the day, with no painfully obvious slowdowns.  So I don't know why my computer is bogging down...especially when I'm not even hitting the same SITE...just hitting a site hosted on the same server.


    But that said, I did follow the instructions that you gave for the Network Utility (above), in case there was something in there that caught your eye:



    Lookup screen:


    Lookup has started…



    Trying ""

    ;; ->>HEADER<<- opcode: QUERY, status: NOERROR, id: 34710

    ;; flags: qr rd ra; QUERY: 1, ANSWER: 1, AUTHORITY: 0, ADDITIONAL: 0



    ;                    IN          ANY


    ;; ANSWER SECTION:          2733          IN          A


    Received 51 bytes from in 5 ms



    Ping screen:



    Ping has started…



    PING ( 56 data bytes

    64 bytes from icmp_seq=0 ttl=48 time=27.926 ms

    64 bytes from icmp_seq=1 ttl=48 time=25.132 ms

    64 bytes from icmp_seq=2 ttl=48 time=29.325 ms

    64 bytes from icmp_seq=3 ttl=48 time=29.303 ms

    64 bytes from icmp_seq=4 ttl=48 time=26.595 ms

    64 bytes from icmp_seq=5 ttl=48 time=27.633 ms

    64 bytes from icmp_seq=6 ttl=48 time=27.863 ms

    64 bytes from icmp_seq=7 ttl=48 time=28.473 ms

    64 bytes from icmp_seq=8 ttl=48 time=29.825 ms

    64 bytes from icmp_seq=9 ttl=48 time=29.147 ms


    --- ping statistics ---

    10 packets transmitted, 10 packets received, 0.0% packet loss

    round-trip min/avg/max/stddev = 25.132/28.122/29.825/1.361 ms


    Thanks again for taking an interest in this and guiding me through these various exercises.  You have certainly pointed me in directions that helped me narrow this issue down (and let me know I'm not crazy).  I certainly do plan to award "points" to you, but I don't want to accidentally end the conversation quite yet in case you have other ideas.

  • Linc Davis Level 10 (192,644 points)

    This appears to be a server issue, not a problem with your Mac. That's about all I can tell you.

  • bug00 Level 1 (45 points)

    Okay, thanks, Linc.  So to summarize...a server can deliver a particular site perfectly fast to all computers except mine (and mine *only* slows down when a browser window on another MBP on the same wireless network is already open to a site on that server).  But it's not a problem related to my Mac. 


    If no other computer is experiencing a slowdown (which no one else who accesses the site regularly has experienced), I honestly don't even know how to begin to tell GoDaddy that this is their server problem...a problem that is only manifesting on my computer.  Any ideas how to broach that discussion?

  • Linc Davis Level 10 (192,644 points)

    I guess I should have said it's a network or server issue. There's no obvious way in which the remote server could distinguish between clients on the same local network, which is what you seem be saying it does. The router could. Third-party routers can do odd things.


    If you want to try something exotic that almost certainly won't make any difference, try this.

    From the menu bar, select

    System Preferences Network

    If the Network preference pane is locked, click the lock icon in the lower left corner and enter your password to unlock it. Then click the Advanced button and select the Hardware tab. Select

    Configure: Manually


    MTU: Custom

    Enter an MTU value of 1280.

    Click OK and then Apply. Test.

    You must apply the change before it takes effect.

    If the issue is resolved, experiment with higher MTU values until you find the highest one that works. The higher the MTU, the better the network interface will perform.

    If changing the MTU has no effect, restore the Configure setting to Automatically.

  • bug00 Level 1 (45 points)

    Thanks, Linc.  Considering that earlier in the thread you felt the network was apparently ruled out as being the problem by the results of some previous tests you had me do, I think at this point I'll just leave well enough alone.


    My network works perfectly for one latop all of the time, and works perfectly for my laptop in all instances *except* for these two urls in certain reproduceable circumstances.  So, it's not worth it to me to mess around with the MTU settings of my hardware...most especially because you said that trying it "almost certainly won't make any difference".  ;-) 


    I do appreciate the time you invested.  If anyone else has experienced an issue like this and gives me a fix, or if I discover anything on my own pertaining to this very specific issue, I'll certainly post back.

  • Linc Davis Level 10 (192,644 points)

    earlier in the thread you felt the network was apparently ruled out


    "Apparently" is the key word. The facts you've stated since then don't fit any pattern I recognize.

  • bug00 Level 1 (45 points)

    Gotcha...I hear you.  When I have a mystery, I guess I have a goooooood mystery. 


    BTW, my curiosity got the better of me.  I decided to try your suggestion of resetting the MTU to 1280 after all, and like you didn't make any difference.  Oh least I tried.

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