Skip navigation

I love comments, but I had to add this due to some of the ones this article has received: please don’t leave comments that complain about this not working and asking for help; if it doesn’t work, your problem isn’t THIS problem, and you need to do good old fashioned network troubleshooting, which is beyond the scope of this article or my generous unpaid assistance.

To make a long story short, I just finished fishing out a problem where a Vista laptop was connected via wireless and the only website that seemed to work was Google.  That is, until I tried another page I have that’s just a one-line message.

WARNING/UPDATE: This solution is not guaranteed to work, and should only be attempted if there is functional network connectivity but issues only arise when attempting to load items larger than about 1500 bytes in size. The default MTU for Ethernet devices is 1500, and modern operating systems use path MTU discovery to auto-correct this value if the MTU is too high. If your MTU needs to be smaller, it should be corrected at the router or modem, not the computer. However, in a pinch, this solution does sometimes work. If it gets worse, then the MTU may need to be even smaller; try 1480, or even 576. Be aware that smaller MTUs can cause slower connectivity.

Details: The laptop won’t load anything but Google.  Attempts to load other pages such as MSN, Yahoo!, etc. all fail.  The status bar says it’s “transferring data from http://www.yahoo.com”; but the Yahoo! page won’t load.  It looks like it’s “stuck.”

Checked everything security-related, dumped every security application just to be safe, but no dice.

Getting into the networking mess of things, I can ping google.com, but I can also ping every other site I try.  DNS servers are correct and DNS name resolution works beautifully.  There’s absolutely NOTHING wrong with the apparent network configuration, and no other computers or devices on the Internet through this router have the same issue.

So, because it’s obvious that everything is set up just fine, I took a shot in the dark and loaded a page I knew was very, very short and small.  This is how I test for MTU (maximum transmission unit) issues, where the largest packet size that can be transmitted across the wire (usually 1500 bytes in size) is set too high, and packets that are too large are simply dropped without notice.  Loading small pages or pages made up of many very small files, but failing to load larger pages, is a blatantly obvious sign of an MTU problem.

So, I had to tap into my command-line-fu and change Vista’s MTU for the wireless connection to see if things would get better, and they did.  Why there was an MTU issue, I may never know, and honestly there should never have been one in the first place…but there was.  Bottom line is this:  if small pages work and large pages don’t, change the MTU on the network interface using a command such as the following one, and the problem will be solved (hit start, type “cmd” in the search bar, hit control+shift+enter, say “continue” if prompted, type the command below and hit enter again):

netsh interface ipv4 set subinterface “Wireless Network Connection” mtu=1492 store=persistent

Replace “Wireless Network Connection” with the exact name of your wireless network adapter in the “manage network connections” part of the Network and Sharing Center.

About these ads

20 Comments

  1. thanks this worked great.

  2. doesnt work :(

    • If this doesn’t work then you have a different problem. Make sure you’ve checked for viruses, spyware, malware, etc. Also, consider the possibility that your security software (antivirus, firewall, etc.) could have broken somehow and may be causing the problem. I’ve seen many cases where a computer couldn’t access the Internet and simply uninstalling McAfee fixed the problem (as one example.)

  3. oh my god. thank you

  4. MTU is a possible root cause of this problem. I’m constantly use a “ping google.com -t” which periodically shows a bunch of timeouts. You mentioned that some packets exceeds the MTU size. I guess a ICMP Ping packet is too small to exceed the MTU size, right? Strange thing: I have 2 network adapters, one bridged to a VM running on my computer. If 2 NICs are connected at the same time in Windows 7 there are strange behaviours of which NIC the system uses. Of course we can set the preffered one in “Network & Sharing Center > Change adapter Settings > Advanced > Advanced Settings > Connections:” and change the order of the NICs. I’ve not found a solution, still have the “can’t browse other sites than google” at random time spans. A refresh works sometimes…

  5. i tried this out and my problem got worse…it doesnt even open google now… so nothing opens!! please how do I reverse it?

  6. Thank you! You solved my problem.

  7. Thank you! Worked. What caused the MTU to change? It was fine yesterday.

  8. same thing with me
    i really need help!
    this didn’t seem to work

    • This post seems to not work in most cases today. Google is a much bigger page than it used to be, so I doubt that this post is very relevant anymore.

  9. I get an error saying the command is not recognized,any idea why? I am using XP SP3 Operating System

  10. incase people still read this, the biggest problem causing this nowadays… is adobe flash player. For some reason the newest update versions will download but at some point your computer as trouble functioning with it. Simply go to your control panel and into uninstall programs,and uninstll adobe flas player. Once this is done open your internet and try to load sites, they should load now, however you cant play video or anything because you dont have adobe anymore, so simply go and redownload it and it should work fine now. This fixed the problem for me and hopfully it will for others.

  11. From a tired IT guy: For me, after testing cables, updating NIC drivers and wasting about 2 hours of my life, I read through this and thought… “Adobe”. Hmm. Uninstalled it… still the same problem. I found out that the user had installed Microsoft Silverlight two days ago. I uninstalled Silverlight… BANG. Everything is running fast and smooth. So… try that if you need to!

  12. Worked like a charm for a wireless router that I used to connect multiple devices in a hotel room. Thank you so much!

  13. Thx Man!

  14. Somebody PLEASE advise how to reverse this!

    I did this, didn’t work. Then I uninstalled Adobe flash (and also needed to uninstall avast to uninstall Adobe…but still have Avira), and the latter fixed the problem.

    However, I want to reverse what I did here.

  15. Had this problem recently with my laptop with win8. You Sir are my hero.

  16. I had this problem where I was not able to access most sites. But apparently Google and Facebook worked. After a long and frustrating time, I found a program called Gorilla Price on my computer. Trying to Uninstall, I was referred to a website with a uninstaller which I had to download. Seemed sketchy so I continued my search. Found a nice uninstaller to get rid of Gorilla Price. RevoUninstaller worked like a charm. Just had to download it via a seperate laptop, then transfer it over to my desktop. Almost instantly, I had access to the rest of the internet. There’s also some files and perhaps an exe called WatGorp that is affiliated with GP. Be sure to disable/delete any add ons or extensions that may have been installed into your browser.
    TL;DR Removed Gorilla Price via free software, RevoUninstaller.

    Hope this helps.

  17. Thank you so much for suggesting to set the MTU size. I have tried everything else and nothing seemed to work. This _may_ have been related to the accidental installation of McAfee Security Plus (bundled with Adobe Flash Player).

  18. Wow… I didn’t even know MTU settings were a thing, and I’ve got quite a bit of experience with networks. I spent two hours troubleshooting somebody’s computer over this issue. I couldn’t for the life of me figure out why the network was working fine but webpages wouldn’t load right. You saved me from going completely insane.


Leave a Reply

Fill in your details below or click an icon to log in:

WordPress.com Logo

You are commenting using your WordPress.com account. Log Out / Change )

Twitter picture

You are commenting using your Twitter account. Log Out / Change )

Facebook photo

You are commenting using your Facebook account. Log Out / Change )

Google+ photo

You are commenting using your Google+ account. Log Out / Change )

Connecting to %s

Follow

Get every new post delivered to your Inbox.

Join 68 other followers

%d bloggers like this: