Take the 2-minute tour ×
Super User is a question and answer site for computer enthusiasts and power users. It's 100% free, no registration required.

When I try access a website, and it is down, I head to http://www.downforeveryoneorjustme.com, and test it. But lately, my home network PCs cannot access facebook.com, and I tried the that service and the answer was:

It's just you. http://facebook.com is up.

Ok, that got me. I tried several browsers and 3 PCs in my LAN and it don't works. I don't know how to troubleshoot this. What some step-by-step to troubleshoot that problem?

Output from ping command:

Disparando facebook.com [69.171.234.21] com 32 bytes de dados:
Resposta de 69.171.234.21: bytes=32 tempo=256ms TTL=245
Resposta de 69.171.234.21: bytes=32 tempo=255ms TTL=246
Resposta de 69.171.234.21: bytes=32 tempo=251ms TTL=245
Resposta de 69.171.234.21: bytes=32 tempo=255ms TTL=246

PS.: I thank you for the nice help, but then I suppose that the first step of a step-by-step to troubleshoot is ping from command line?

share|improve this question
2  
Can you go to a cmd prompt and ping facebook.com, and edit your question with the response? –  Paul Oct 28 '12 at 23:57
    
also, try ipconfig /flushdns' and check your hosts` file to make sure you're not being spoofed. What is the DNS your router is using? –  kobaltz Oct 29 '12 at 3:14
add comment

closed as off topic by MaQleod, 8088, soandos, Indrek, Diogo Oct 29 '12 at 11:01

Questions on Super User are expected to relate to computer software or computer hardware within the scope defined by the community. Consider editing the question or leaving comments for improvement if you believe the question can be reworded to fit within the scope. Read more about reopening questions here.If this question can be reworded to fit the rules in the help center, please edit the question.

2 Answers

I'm not going to go down the virus/malware approach as you have tried from several different machines. As Paul said, please verify the IP of facebook.com just in case there is something wrong with your router.

That being said, over the past few days, there has been many critical internet routes that have gone offline (See here for more information).. It is possible that your ISP is only peered/connected with routes that are down and you can't connect to Facebook because of this.

If it is only in the past few days, I think this is the most likely cause... If it has been a lot longer, and there isn't a problem with your machine/router, I would contact your ISP.

share|improve this answer
add comment

ISPs mess up. I personally tend to do a few things to check if a site is really down

  1. Traceroute (or tracert in windows). Ping tells you if a site is down. Traceroute tells you where its down

  2. Use a proxy - I run my own on a VPS, which is probably better than using some random proxy, or you could use tor - the tor browser bundle is an easy way to do this.

  3. Try switching DNS servers - I tend to favour the two google servers (8.8.8.8 and 8.8.8.6) to rule that out

share|improve this answer
add comment

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