I can’t access some websites … why?

Sometimes not being able to access certain web sites boils down to a simple network configuration tweak that I'll detail here.

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I can visit a lot of web sites on the internet without a problem. But a few simply don’t work. The strange thing is that they work for other people, or from other machines. What’s going on?

I touched on several possibilities for this in a previous article: Why can I not access certain web sites?. I’d certainly recommend that as a starting point.

However, since that article was written, an additional reason for some web sites not being accessible has surfaced that’s worth looking into in a little more detail.

It’s very obscure, but the good news is that it might also resolve some other problems, most commonly problems with instant messaging.

The issue is an obscure setting called “MTU”, which stands for Maximum Transmission Unit, in the network configuration. I’ll describe it in a little more detail in a second, but first if you’re having a problem, let’s look at your current setting, and perhaps try tweaking it.

MTU is buried in the registry, but rather than edit the registry directly, there’s a small program you can download for free that will allow you to view and change the MTU settings: DrTCP. Download and run the latest version, and you should see something like this:
DrTCP screen shot
I know it looks a little intimidating, but don’t worry. We’re going to pay attention to only the two items in Adapter Settings. You can safely ignore the rest.

First we need to make sure that the correct network connection or “adapter” is selected. Even if you have only one network connection, there are often several others. In Adapter Settings the field on the left is a dropdown list of all the network adapters on your system:
DrTCP Adapter Dropdown

 

If the MTU setting is causing you problems accessing some web sites, it’s probably because it’s set too high.

Make sure that the adapter that corresponds to your internet connection is selected. Normally that’ll be the adapter that provides you your “Local Area Connection” – as you can see in my case it’s an Intel PRO/1000 card. Once it’s been selected, the field on the right within Adapter Settings will show the MTU setting currently in use for that adapter.

If the MTU setting is causing you problems accessing some web sites, it’s probably because it’s set too high. As you can see my default is 1500, which is appropriate for an ethernet connection, and probably the highest you’d ever want to see it. Unless you’re on a dial-up connection, larger numbers make for a somewhat faster network connection – unless it doesn’t work at all.

Write down the MTU value you found to start with, and then try these values
in order:

  • 1492
  • 576

Do that by replacing the value in the MTU field (again, making sure that the correct adapter is selected), and clicking Save, and then Exit. You will then need to reboot and test to see if the new value has corrected the problem.

Important: if the smaller values don’t resolve your problem, then do remember to reset the MTU value to whatever it was when you started.

So that’s all been pretty much black magic and obscure numbers. What does it all mean?

When information is transferred across a network, it’s broken into chunks called “packets”. The Maximum Transmission Unit is related to the largest packet size that your computer will attempt to send.

Each packet has “overhead” – information that is not data, but rather information that says things like “I’m packet #13, coming from this IP address, heading for that IP address”. Larger packets are more efficient in reliable networks, because since the overhead is fixed per packet, you spend a higher percentage of your time sending actual data and less on overhead. A 1500 byte packet with 1460 bytes, or 97% real data is more efficient than a 576 byte packet with only 536 bytes, or 93% data. There are also other factors including latency, packet delays and the like that make larger packets more efficient.

Unless the network is unreliable. That’s why you’ll often see smaller maximum sizes on dial-up networks. If a packet gets lost, which does happen from time to time, a smaller packet is more efficient to re-send than a larger one.

You can see that it’s not just magic, but also fairly complex.

But it does boil down to the characteristics of the network between you and the site or service that you’re attempting to use. The “standard” values for MTU are typically:

  • 1500: direct connection to an ethernet network, and many broadband connections. As you saw, this is the value my machine uses, connected to my LAN, which in turn is connected to a router and a DSL connection to the internet.
  • 1492: certain types of connections (some types of PPPoE) require this value, and if you’re having a problem actually related to MTU, there’s a high likelihood that this value will in fact work for you.
  • 576: the default value for most dial-up connections.

If you’re connected to the internet via equipment that requires a smaller value, or, while rare, the remote site you’re trying to access is connected via equipment that requires a smaller value, you’ll simply be unable to connect. Adjusting your MTU value is one thing to try.

Update: another common reason for not being able to visit certain websites is detailed here: Why did my home network stop working?

Update #2: another very common solution is to clear your browser cache. More here: What’s a browser cache, how do I “clear” it, and why would I want to?

There are 85 comments:

  1. Walt Reply

    My wife can access all web pages from a wired connection, but when she goes wireless on the same computer, only some of those same pages can be accessed. For example, she can connect to the main page and some sub pages of U-Haul’s web site but not to other pages (specifically http://store.uhaul.com/hitches.aspx). Would changing the MTU setting help with this situation? Thanks.

  2. Bruce Reply

    Two reasons I have had for not reaching some websites are:
    1. The host file, when the link uses an intermediary advertising link like fastclick, which is in my hosts file. I remove the intermediary link from the address bar and go to the desired destination.
    2. The javascript used is not completely proper and the browser I use does not handle it, but IE does handle it.

  3. Rick Reply

    I wasn’t able to get to some sites. I’m on XP home and have DSL. I have an dhcp assigned ip, but was using my dsl providers DNS entries for my network card. I got rid of the dns entries and the sites I couldn’t get to showed up immediately. I’m guessing it was a temporary dns issue on their end. I thought adding a dns entry would speed things up. It worked since I setup my system three weeks ago, and all of a sudden just stopped. Go figure.

  4. Matt Reply

    hey!! wow i love you man lol i cant belive it you fixed it!! ok well make sure you put down MTU numbers that he tells you to and not the ones that he has on his because i didnt listen lol and first i put 1500 and it didnt do anything but then i tried the 1492 and it worked .. oh and if you have windows xp you dont have to reboot you can just go into controll panell and then go to network connections, right click on ur connection and then click disable then enable it again by right clicking on ur connection and clicking enable

    this made me able to get onto windows live messenger again and log onto myspace and onto hotmail so if you have those problems i strongly recommend this

  5. james Reply

    ok I have what I consider a different scenario from the ones above. I cannot get to this website but I can ping it. I attempted it from my mother’s pc which is a different setup browser etc and it had the same no response. But I could ping the website from my moms computer also. We are on DSL with a wireless network for my pc. so I decided to by pass the router and plug my moms computer directly into the DSL modem. Did that and still could not access the website. So it’s not my router. SO i tried tweaking with the modem different things. I reset it completely. Disabled all firewalls. Still I can’t get to this page in IE or Mozilla. BUT we have AOL for broadband that connects over our DSL connection. The bizarre thing is I can connect to the website through the AOL portal. Just not directly through Mozilla or IE. There is something that is simple that I am missing. Someone please point it out.

    I would like this resolved so that I can get to it through my preferred browsers. I don’t really use aol for broadband much and we are fixing to delete the account.

    I appreciate any help you might could give.

    I am kind of in the thinking that some how maybe my dsl carrier could be blocking the site but I have no idea how that would work or why.

  6. Adrienne Reply

    Hello, I recently installed a router to connect an additional computer at home for a total of to internet accessable computers, the first computer works as it normally did the second however will not access email, java downloads, and many others, all I can get is the page cannot be displayed page directing me to internet options, my isp assistant me in making sure the internet options were proper as did the router sales rep but nothing has worked to remedy the problem, please help
    Adrienne

  7. terri Reply

    Every time I try to log on myspace.com I will get a message saying internet explorer cannot display the webpage. I have tried everything I tried what you mention above and still cannot access myspace, this problem just occured a couple of days ago, please help.

    Thanks much,
    Terri

  8. Michael Workman Reply

    I read this thread…with so many solutions. I tried each one…but the answer for me was the one where they suggested that you change the dns setting in TCP from dynamic to a specific address of my router. That worked! I had fought this for HOURS… Thanks to all the contributors on this thread, i am now growing my hair back in.

  9. Kevin R. Reply

    Thank you very much! I would have never thought that the MTU was causing the issues I had on my home network.

    I didn’t use Dr. TCP. I went into the setup page of my Linksys router via my web browser (192.168.1.1) and found that I had the MTU setting disabled. Once I enabled it and set it to 1500 it fixed the problems I had with not being able to access certain websites. Thanks.

  10. Jay Reply

    Quoting Terri, “Every time I try to log on myspace.com I will get a message saying internet explorer cannot display the webpage. I have tried everything I tried what you mention above and still cannot access myspace, this problem just occured a couple of days ago, please help.”

    Same Problem here, any suggestions? Not only Myspace either, there are a few others which I cannot access, including my work email!!
    It was fine 2 days ago, but yesterday and today……. NIGHTMARE!!
    Many thanks for any suggestions!

  11. Denis Mahoney Reply

    Leo-you’re the man!
    Your suggestions led me to do the following which fixed my Belkin Wireless not connecting to Hotmail.
    I installed the Microsoft TCP v6 (comes with XP) which included Turedo Tunelling so this handled the NATing side.
    I adjusted the MTU on my wireless card (previously had just been changing it on the Belkin router).
    Both of these changes-inspired by you-fixed my long standing problem-many thanks!

  12. Jubilee Reply

    I tried the MTU settings, but when I did it everything was blank or set to default. I still tried the two different settings and it’s not working. I can’t access myspace from home on either of my computers but I can at work using my laptop, so I believe it’s something to do with my internet. I tried rebooting the box and the router but it didn’t work. Please help. I have family all over the world and this is the only easy way we have to keep in touch.

  13. Stuart Woodard Reply

    Some folks are having trouble using DrTCP on Windows Vista. I must admit it has worked fine for me, but you can make the registry change yourself.

    The Vista registry key is:
    HKLMSystemCurrentControlSetServicesTcpipParametersInterfaces

    Under this key are a number of others, including one for each of your installed network cards/devices. You can find an MTU subkey under each device and change the (DWORD) value to whatever you like. I chose 0×00000578 (1400).

  14. peter ray Reply

    My Belkin ADSL2+ Modem with Wireless G Plus MIMO Router have a defaulted MTU = 1432. I change to 1492 as suggested by Leo and now i can access to microsft & msn. I wonder if Belkin have some bad blood with microsoft or sometihng2.. anyways,. Cheers to Leo…

  15. Amrisha Reply

    Hi Leo,

    Nice site! :)

    I do have a wireless connection problem, hope you can help to resolve the issue. See, the problem is we do have an internet connection (1 laptop is fully connected and can browse all sites) and the other can only access certain sites. I have tried most things but seem to fail.

    Can you kindly respond in this situation…

    Many Thanks,
    Amrisha

  16. Leo A. Notenboom Reply

    —–BEGIN PGP SIGNED MESSAGE—–
    Hash: SHA1

    No way to know without knowing how everything’s connected and configured.

    Sorry.

    Leo

    —–BEGIN PGP SIGNATURE—–
    Version: GnuPG v1.4.7 (MingW32)

    iD8DBQFG0zlMCMEe9B/8oqERAhhiAKCFRBIJx2Cyuu2rLS4tf04/BogzJACcDrFf
    qnjZswTTkPwICH1jNeB/fIs=
    =53vf
    —–END PGP SIGNATURE—–

  17. Dean Allen Reply

    Hello, firstly my windows xp professional is in spanish, i don

  18. John Stuart Reply

    I am now going to call you Dr Leo!!! Even Saint Leo! I have been battling all week with problems on my small business network – client computers just started having problems connecting to websites without any explanation. I don’t know why this happened but I have tried everything to fix it. Tried your DrTCP device and even though I didn’t have any MTU value, setting it to 1492 has cured all problems. Thank you!!

  19. kobi Reply

    hi leo
    i cant see any where to start a new question on this site so ill post this here and hopefully youl be able to help , i had a power cut and put this XP PC in the fixit shop to get past the “blue screen” since ive had it back the “desktop backgrounds” have been dissabled in display options , theyre still there but non selectable and unable to scrole them up or down , the colour options are active and thats about it – when i go to a picture and right click and choose set as background the image doest apear , allthough when i boot this PC up it shows the background ive selected and then it dissapears when my desktop loads and all i can see is one of the color options and sometimes when i have a glitch on the desktop display i can see the image showing through the glitch, ive google this extensivly and found many other people having the same problem but with no answeres, i did find something on the windows help page about background wallpaper probs , they say to go into the (MMC) microsoft management console) and open –

    Local Computer Policy
    User Configuration
    Administrative Templates
    Control Panel
    Display

    but when i go into the MMC theres nothing there to open “im abit unsure to say the least” ????
    link..http://support.microsoft.com/kb/280687

  20. Lori Martinez Reply

    If I could plant a big ‘ole sloppy kiss on ya Leo, I would! Thanks so much for this ingenious information. I’m so glad I Googled my problem and found this site. You’re awesome!

  21. James Reply

    I tried the MTU settings and like another fellow I have no numbers as well using XP Home Edition on your basic cable hook up. No router. The only site I can not get on is the most recognizable site out there…google! Anything to do with google and I won’t be able to get on. I’ve changed my search engine to Alltheweb.com for this reason and just lead my life without google. Any help would be appreciated. Thanks

  22. Jamure Reply

    I had to use another computer to down load DrTCP and transfer it to my computer with this same problem … it did NOT fix the problem.

    SOmething else is wrong. Whatever it is – it is pretty smart … I cannot download windows updates, virus scan software … those websites do NOT work or gets stuck after a while …

    I tried web based scanners (from the websites that I can access) – nothing comes up after several hours of scanning.

    this computer with problem has

    Windows XP Professional SP2
    Websites like Yahoo, Google do NOT work few others (www.msn.com) work fine
    I have been trying to fix this problem for the last 7 days about 40-50 hours spent so far.
    I am not totally computer illiterate …

    Other machines (laptops) work fine through the same ISP and router!

    Couple of experts I spoke with in my town said they had similar problems and ended up reinstalling Windows and starting all over again with their machines that are taken over by this demon, whatever it is.

  23. Jamure Reply

    Additinal Info:

    I started my computer in SafeMode — ie SafeMode+Networking mode — and the websites that did not work before seem to work now — so whatever the problem is getting kicked in only when we start the windows in full mode.

    For people who don’t know how to start SafeMode — start hitting F8 key while your system is booting up like crazy — it will take you to a screen where you can use up and down arrow keys to select SafeMode with Networking. If you start just SafeMode (without the Networking loaded) then you cannot access anything outside your own computer – no internet, no other computers.

  24. Alex Reply

    Hey Guys,
    Just Wanna let you know I was able to Resolve the problem.

    I tried Turning Off the Hosts File via CMD and the site worked, so I went ahead and opened the Hosts file with notepad and search for the the website I was trying to access.

    For some Weird Reason, it was added to the block list with an loop Ip to resolve on.

    Cheers.
    Alex

  25. Josh C Reply

    Yes! This worked perfectly. For some reason, all of the domains I own (which are all hosted from the same IP) went dark for me. I couldn’t see a single one, but everyone else in the world can. So, I did the instructions above, however, my MTU had nothing in the box, so I entered 1500 and presto! I could see all of my sites again.

    Thanks!

  26. Cheri Reply

    I have AT&T Wireless broadband on my laptop and I can’t bring up the http://www.hotmail.com sign in page all of a sudden today; yet, I can on my iPhone. Is this a provider issue, hotmail issue, hurricane issue (I’m in south Texas) or something else? I can get on every other site out there.

  27. Amanda Reply

    I bought a new Belkin Router this morning. It has taken 4 hours to set it up. I have been phoning Belkin and my broadband provider. I managed to get onto the internet in the end. But no Hotmail or Yahoo. Just want to say thank you for the advise on this page because it worked for me.

    The Belkin MTU was set at 1439. I changed it to 1492 and it now works. Thanks

  28. Bob Reply

    I tried to download DRTCP, however, I just got message “THE WEBSITE DECLINED TO SHOW THIS WEBPAGE” HTTP 403. Obvious there is something that I should be doing and as I am not quite illiterate with PC’s, there is still alot to learn. Any suggestions to rectify the situation.

  29. Gbrode Reply

    I am unable to access sites through search engines, Yahoo, Google, etc. but can access any sites I have bookmarked including any any links from them. I can also sometimes access them if I type the address in the URL. I did a system restore and all was ok for a few days, but the problem returned and doesn`t always correct itself after a restore. I tried swapping the computer over and found the same problem. I would be grateful for any halp.

  30. J Reply

    I have this same issue. I can access a site and then 20 minutes later its not found. I know there is nothing wrong with my machine or the site. Because i can still visit other sites. I can use another computer to visit the site or use anonymizer sites to visit the site…so what is the actual issue here?

  31. Ton Reply

    Thanks Leo,
    I ran into this problem when I rearranged my home network through my Linksys Wireless Router. I used to connect the ICS host (internet connection sharing) through the router via wireless connection but now plugged in an ethernet cable. And since then had problem om my wireless laptop. Other sites also suggested this was a Linksys problem and might have to replace it. But you solved it. Many thanks!

  32. asivakumar Reply

    when i open up Dr TCP in the MTU there is nothing in the box. I uninstalled msn messenger rebooted and everything works

  33. CPUGURU Reply

    It is not your MTU, it is your HOST script in Windows..To fix this go to:
    c:/Windows/System32/drivers/etc/Hosts
    You might find someone has changed your settings causing a loopback… This is all you should see in your HOST script..

    This is a sample HOSTS file used by Microsoft TCP/IP for Windows.
    #
    # This file contains the mappings of IP addresses to host names. Each
    # entry should be kept on an individual line. The IP address should
    # be placed in the first column followed by the corresponding host name.
    # The IP address and the host name should be separated by at least one
    # space.
    #
    # Additionally, comments (such as these) may be inserted on individual
    # lines or following the machine name denoted by a ‘#’ symbol.
    #
    # For example:
    #
    # 102.54.94.97 rhino.acme.com # source server
    # 38.25.63.10 x.acme.com # x client host

    127.0.0.1 localhost
    ::1 localhost

    If for some reason there is anything else just delete it and save!! If you are using Vista you must access this file as an admin or change your privelages…Hope this helps some people!!!

  34. cameraz Reply

    Thank you so much, Jaco!!!!!! I have been trying to solve this problem for years! In fact, today I called my antivirus program manufacturer and complained that its product was blocking me from seeing some Web sites. They had me disable my antivirus and I still couldn’t access the sites!

    After reading your response, I checked my Hosts file, and, lo and behold, there were hundreds of entries placed in there!!! The culprit? Spybot Search and Destroy!

    I removed all the entries, saved my hosts file, and Viola! I can access all the web sites that I couldn’t before.

    Again, many thanks!!!!

  35. shaun Reply

    Many Thanks, I ended up just deleting the hosts file (after making a copy of it – just in case).
    Then I could access all sites including Google.

  36. Stanley Reply

    I’ve tried what it suggest by altering the MTU, but still doesn’t solve my problem from login into a forum and game website which i been login in for 2 years. the websites are as follows : engforum.lastchaos.com.my & http://www.lastchaos.com.my . i’ve tried on other PC and it works fine. I’ve even tried ping both of the websites and it replies as normal. i just couldn’t access it through my internet browser. whenever i typed it on the address bar, it just keep waiting for page to load and in turn fail to load. hope there is someone who could help.

  37. Randy Christianson Reply

    Super advice!!! Thank you so much. After tearing my LAN apart, disconnecting routers, switching out modems and spending two hours on the phone with my ISP tech support I was awaiting a site techs arrival. I found your site by accident, checked on a whim and discovered all MTU’s were set to 0.
    I reset them to 1500 and the results were amazing
    I can now access sites I have been unable to get onto for months.

  38. Neakhiz Reply

    I’m experiencing a problem accessing ANTIVIRUS websites, I,ve visited a lot of forums for a possible solution, I tried to scan my computer with antimalware, antispyware and antivirus on safe mode, deleted all files on “Temp” folder, but still I cant access antivirus sites, i dont know if theres still a virus/malware lurking in my CPU or its just a setting that was changed by that virus, funny thing is only antivirus sites is one I cant access, (AVG, Avast, Symantec, kaspersky, Avira, PAnda, nod32, bitdefender,Norman…..etc)I’m actually using AVG 8, now my AVG’s virus database is outdated since I cant update it, I used Avira, SuperAntispyware and Malwarebytes to scan in SafeMode, things are going fine, scanned some malware, cookies and virus, not I think its already clean and Zero Virus, but when I tried to access those said sites…. theres no luck, still I cant access Antivirus Sites, Pls help! thanks in advance!

  39. Jade Anderson Reply

    Hi there im currently running on windows vista i am having trouble going on to websites ive been on before (days ago) i can log onto them from another website so i know there is no problem at there end and ive downloaded the drtcp but it comes up blank and too be honest not really sure what im doing :{. Does anyone know what this could be? thanks

  40. Mr. Smith Reply

    I have a simular problem. I have a webpage that refuses to load. Ive checked everything, twice. Do different things from other sites but no luck. Page simple turns and states done on bottom left. No text no pictures. Running xp and Kaspersky.

  41. J Reply

    I read both articles and was wary of using the above suggestion. I would use it but, I just wanted to throw out what worked for me. I was having difficulty accessing a site that I’d used several times. It occurred to me to try resetting my modem. This did the trick. Simple fix!

  42. Hi Reply

    does this method affects internet speed??

    Not typically in any way that you’d notice.

    - Leo
    19-Jun-2009

  43. Malcolm Reply

    My MTU was blank; I tried an MTU factor of 1492 and then 1500. On both occasions when I brought up DrTCP the values had returned to blank. Still can’t get Rapidshare and Amazon.com

    Malcolm

  44. Spritz Reply

    I ran this program and my MTU value was blank. Entered a value of 1500 and saved it. The sites that I was having trouble viewing worked perfectly. Thanks.

  45. anna Reply

    Unfortunately, i cant access any of the pages that provide that program. Is there any way to do the tweaking without downloading it?

  46. Hector Reply

    This was the only solution that solved my problem. What I was wondering is why, after reformatting, the problem still occured…

  47. Joanne Reply

    Someone suggested on this site suggest I reset my modem…and it did the trick! Thanks!

  48. Carolyn Reply

    Mid-morning yesterday I started being unable to access the Livejournal site. Error mess. indicates the server is disconnecting from me. MTU would not seem to be the problem, as that didn’t change yesterday. Any idea what’s gone wrong?

    On top of everything else, pay attention to the news too. LiveJournal may have been affected by a denial-of-service attack that affected other sites. Try again tomorrow.

    Leo
    08-Aug-2009

  49. Rafael Reply

    I used an Internet Accelerator, a software that “optimizes” my network connection values, and all was ok but i couldn’t access webpages (important ones by the way, like hotmail). I used the value of 1492 in both of my ethernet cards using the software here suggested (original values were 1500) and rebooted. Now all pages work!!! and messenger is also on track. I don’t know if this was the root solution, but after i did this, everything worked immediatly. Thanks!

  50. Mike Reply

    i cannot access one particular website anymore….rapidshare.com
    i have a Rapidshare premium account.
    Since yesterday, anytime i try to download anything through Rapidshare, the following message eventually appears….

    :irc-2.test.com 451 GET :You have not registered :irc-2.test.com 451 Accept: :You have not registered :irc-2.test.com 451 Accept-Language: :You have not registered :irc-2.test.com 451 UA-CPU: :You have not registered :irc-2.test.com 451 Accept-Encoding: :You have not registered :irc-2.test.com 451 User-Agent: :You have not registered :irc-2.test.com 451 Host: :You have not registered :irc-2.test.com 451 Connection: :You have not registered ERROR :Closing Link: [118.33.225.52] (Ping timeout)

    Also, when i try to access Rapidshare.com i get the same message.

    Can you please help me with this problem?
    Thank you

  51. Samantha Reply

    I have the same problem, with a twist.

    My own website that I am just starting to build was easily accessible for three days. Now I cannot get to it from my computer at home but I can get it from another friend’s house and from the library. The server the site is on has no problems since the site is accessible from other computers.

    I work with an Imac. I called Time Warner, my IP and that was two days ago. They told me a technician would call me within 24 hours but have not heard from the person.

    Can someone please help me. I already did the basics, clean cookies, reset Safari, tried Firefox, same thing happened.

  52. selva Reply

    Thanks! you saved me from formatting my hd! It works for me!

  53. Karen Reply

    I can go on a multitude of websites however the website I can’t get on is my husband’s reunion website – I went into options and exceptions and added that website to be allowed – I have been on it once by some MIRACLE and haven’t been able to get on it since. Any ideas?

    Karen

  54. Susan Reply

    I ran the program to change my adapter and MTU. The adapter was wrong and MTU was blank. I selected the correct adapter and typed 1500 in MTU and pressed saved. I rebooted and problem still exists. When I re-opened your program, it went back to the old adapter and MTU was blank? Can you help?

  55. Rupert Dick Reply

    I found the best way around this was to configure the router to the internet. I set my Dlink to its default (1500, rebooted the router and that worked a treat.

  56. Tom Reply

    Doesn’t work, I tried all the values and the results are still the same. Using Vista.

  57. Petet Reply

    Peoples can not access many web sites, and the first suggestion is to download a tool from web site who is not accessible!….
    http://www.dslreports.com/drtcp

    If you can’t access that website, then download the recommended tool from another computer that can.

    Leo
    08-Dec-2009

  58. Tim Reply

    I had this problem for days…tried everything suggested on many forums. ran virus checkers, anti malware, spybot, rebuilt my ip stack, cleared temp files, used winsockfix….the list goes on and on.
    Eventually I re-intstalled my router out of desperation…all working fine now.

  59. Mike G Reply

    Leo–you are a genius. Thanks so much for the information on MTU. I’ve used Dr TCP and can now logon to websites (mainly financial)that I’ve been barred from for more than a year. A real Christmas present–cheers!!

  60. Dan McMenamin Reply

    Have vista on notebook, no work…da nada
    internet/network is fine on another laptop and my desk top.
    HP told me to uninstall IE8, which I did and then reinstall…which I did.
    Still unable to to see web pages. Connection read fine…tried firefox too…nothing
    what Gives? Any one have a solution?

  61. Jan Lippus Reply

    I cannot access any web sites using anything to do with the Ohio National Guard. Other people can even those on the same IP. This is the only web site that will eventually download, but takes sometimes up to 10 or more minutes. I use this site a lot.

  62. Andrew Reply

    i have had this problem for around 4mths now. i can not access a couple of websites. I have run Avast, Superantispyware,spybot,Malwarebytes’ Anti-Malware and i have a comodo firewall. i have cleared all the cookies,history and offline files. i have used Dr Tcp to reduce my MTU by 10 at a time from 1500 to 1400. i have reset my Netgear wireless modem router to default settings. i have gotten on the Netgear forum and they have come to a assumption my ip address has been blocked. I have tried everything mentioned in the related articles and still no joy.Very frustrating. Any else i should try?

  63. Steve Myers Reply

    OK… I had this problem after I was infected with some malware or adware. It came up with a Fake ‘Windows Secyrity Alert’. and directed my computer to a FAKE Anti-Virus website. I was able to clean it out with AVG Internet Security… Then after 3 weeks, “IT” came back and after running AVG in Safe mode ‘F8′ it was cleaned out again. But then, I could not access certain websites. For days I tried eveything… Including, CCleaner, to clean up the Registry. But to no avail. Then, while talking with my brother….. he told me to check ‘Internet Options’, ‘Connections’, ‘Lan Settings’… It was set to ‘Use a Proxy Server’… I set it back to ‘Automatically Detect Settings’. PRESTO… Everything is back to Normal. Appearantly, the ‘adware’ set itself up as the Proxy Server….
    Very Simple. Good Luck.

  64. Charlene Reply

    You rock Leo!!!!!! Thanks so much for your perfect help with my issue accessing some websites. It was a nightmare and not even my ISP could help. YOU DID! Brilliant!

  65. Martin Reply

    I have a very simple piece of advice for anyone with this problem and it might save you hours of frustration. CONNECT YOUR ROUTER BY WIRE instead of wirelessly to see if the problem disappears. This is how I located the problem after over a month of trying every suggestion under the sun. The router was faulty and eventually Belkin to their credit replaced it free of charge with the latest model and now I can access all those sites that I previously could not!

  66. Billy Reply

    If all the suggested solutions fail which they did for me, unfortunately, check your IP address with http://whatismyipaddress.com/blacklist-check. It seems that if you, or more likely, your ISP has been blacklisted then no matter what you do you will never connect to those unobtainable websites. You have to complain to your ISP and they have to take action to be de-blacklisted. Here is my listing on the blacklist:
    “”Who is responsible for this listing?
    YOU ARE NOT!. Your IP 2.***.**.*** was NOT involved in a spamrun, but has a spammy neighborhood. Other customers within this range did not care about their security and got hacked and started spamming, while your provider has possibly not even noticed that there is a serious problem.
    We are sorry for you, but you have chosen an provider not acting fast enough on spammers.””
    I have complained to my ISP and they say it will take 2-3 days to fix. I will be asking for compensation in the meantime. All the best, Billy

  67. Daniel Lugtu Reply

    Try Internet explorer and Firefox instead of Google Chrome.

  68. John-David Reply

    Hi, I got windows 7, but I cant access otaku-studios.com , my mobile, my friends everybody can get on it but I cant… and your tut is for winxp …
    What shoul i do ?

  69. jzguha Reply

    Hi, i can’t access social networking site sch as yahoo, g mail, Facebook etc… I use to get msg box(the site is untrusted). I have window xp.
    what should i do?

  70. Thomas Reply

    what if i download the DrTCP, i open it, and the MTU and other boxes are empty??

    That’s common. The system is running with default values.

    Leo
    10-Mar-2011

  71. Dataman Reply

    Thanks Leo,

    After 2 days of trawling the net to find out why I couldn’t log on to our own web site and pull back emails from a PC on our simple network. Spending countless hours trying all the solutions and waiting for the PC to reboot – finally Dr TCP solves it for me.

  72. Kai Reply

    omg. I don’t know what’s going on, but entering that number(1492) worked like a charm.
    Thank You so much!

    I couldn’t access Yahoo!, YouTube, Facebook, Google. >.>; Those are like the main websites I go to. =.=; You don’t know how thankful I am right now. xD TYVM!!!

  73. CpLKaNe Reply

    Alright, I’m at wits end. I have tried everything possible, but I still can’t access a few select sites such as http://www.xbox-360.co.za or http://www.verydemotivational.com and it’s accessible from every other damn access point on earth. I’ve done every possible MTU setting change, reinstalled my browser, asked my ISP’s tech support, AND NO ONE KNOWS WHAT THE HELL’S GOING ON!!!!!!!

    Let me try to explain: When using Firefox, I try to go to, e.g. http://www.xbox-360.co.za, and the text at the tab says “Connecting…” and at the bottom it just says “Waiting for http://www.xbox….”
    I have pinged the website. 4 packets were sent, 4 were returned, 0% data was lost.

    Rebooting I have tried too many times to remember….
    I have had this problem for nearly a year now. If you have the solution for this problem, I will be forever indebted to you. Please help, if possible.

  74. Tracie Begani Reply

    I am currently taking on-line courses through University of Phoenix. They have a virtual desk top so we can access needed software through their site. Up until Sunday everything was working great. However now, I am unable to access the site through mine or anyone’s computer/internet in my area that has centurylink for a provider. I can access it through both my computer and my friends computer if I use her internet access that is through Wild Blue. I have spent countless hours on the phone with tech support both from UoP and Centurylink and no one can come up with a solution to allow me to access the site from my home. Do you have any suggestions for me??? As no one can figure out what is happening. Would your suggestion about using Dr. TCP be a possible solution?

  75. Cindy Reply

    Just want to drop you a note of thanks Leo! I was struggling with trying to access a particular website for days, and I tried the solution above, and it worked immediately. Thank you – you saved me from kicking my pc in LOL!

  76. Toby Reply

    Hi Leo, I’m having the same issue but I am on a vista machine and could’t run the DrTCP. Please help

  77. Danny Reply

    Thank you This fixed my problem when nothing else would!

  78. Vips Reply

    DrTCP worked on windows 7, it fixed the problem indeed. Thank you

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