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Since 3 days ago I can not open (from outside Brazil) the site UOL. First I thought it could be off line. But 3 days! It is a very big Internet web site and host.

I tried with FF and Google, but nothing.

Then I decided to try ping www.uol.com.br and the outputs looks like

64 bytes from 200-147-67-142.static.uol.com.br (200.147.67.142): icmp_seq=20 ttl=241 time=253 ms

So I guess that the site is online. Is it possible they blocked my access? Or did I do something and blocked myself?

Does anybody abroad can open it?

Edited: using a VPN I can now open the site. So it means that something is blocking my access?

Edited 2 it could be related with IPV6.

Sigur
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  • I can open it from EU – kos Jun 18 '15 at 19:49
  • @kos, so could the problem be with my computer? How? – Sigur Jun 18 '15 at 19:50
  • It might be something about your ISP. Have you tried just typing the IP address instead of the domain? – kos Jun 18 '15 at 19:51
  • @kos, with 200.147.67.142 nothing happens. The status bar shows waiting answer – Sigur Jun 18 '15 at 19:53
  • Weird entries in /etc/hosts? – kos Jun 18 '15 at 19:56
  • Only some lines below # The following lines are desirable for IPv6 capable hosts – Sigur Jun 18 '15 at 19:57
  • But thinking about it if you can ping it it should be none of these problems. Switching the browser? Sorry, not really an expert, just throwing ideas. – kos Jun 18 '15 at 20:01
  • @kos, thanks. But I've just installed Google and the same problems. I only remember some days ago to create a hotspot to share my connection with my mobile. – Sigur Jun 18 '15 at 20:02
  • Last shot in the dark, then I'll pass to someone else. Try to explicitly tell your browser to connect to port 80: 200.147.67.142:80 – kos Jun 18 '15 at 20:05
  • @kos, no. Nothing. Let's wait if somebody can offer something. Thanks. – Sigur Jun 18 '15 at 20:07
  • It might be possible to ping a server but still being unable to connect to ports if some firewall setting are dropping packets to that port but letting igmp (ping) packets through. As other IP addresses are able to browse that server you might want to try some kind of proxy like tor and privoxy. – Henrik Carlqvist Jun 18 '15 at 20:21
  • @HenrikCarlqvist, I'm afraid my Galaxy could had affected my laptop. Or since I use Linux, it is not so easy to attack my laptop? – Sigur Jun 18 '15 at 20:24
  • Are you tethering with your Samsung Galaxy phone to connect your Linux computer to the internet? Somewhere there might be a firewall setting blocking HTTP packets between your Linux machine and www.uol.com.br. That firewall might be at uol, at your ISP, at your phone or at your laptop. I would not say that any OS is easier to attack than any other, it is mostly about having a good configured system with only carefully selected services open (maybe protected by a firewall) and keeping the system up to date with security patches. With your proxy (VPN) solution you were able to avoid the problem. – Henrik Carlqvist Jun 19 '15 at 09:15
  • @HenrikCarlqvist, thanks for attention. I should close the post since I discovered that the problem is related with a kind of security certificate which we use for internet banking and it is blocking to access some pages when we are using ipv6. This is what I understood from the web. But I'm not sure. Before I discovered it I suppose that my mobile could be infected and affected my laptop. Fortunately it is not the case. – Sigur Jun 19 '15 at 12:39

1 Answers1

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Your ping output states that a ICMP packet was able to reach and be replied to in about 253 milliseconds.

64 bytes is the packet size, you can change the size. Changing the size is useful in trouble shooting some network issues.

200-147-67-142.static.uol.com.br (200.147.67.142)

That is the reverse IP DNS lookup address and ip address for the address you requested. It can be used to make sure your hitting the server you intend to hit, especially in clustered or DNS-RR setups.

icmp_seq=20

is the number of the packet. You can use this to detect issues with bad routing. For example getting back packets 19, 17, 20, 22, 21, 12, 23 would mean each packet is taking a different route, and some of those routes are slower then others. Basically you want these to go in order.

ttl=241 time=253 ms

are timing numbers. ttl can usually be ignored. It has a lot to do with timing between hops. It's useful in some rare circumstances, but the higer the number the more the hops (though there is no direct correlation). The TTL should generally be the same. If it's not, then you have to look at other things to figure out why. "Time" is the time for the round trip. Lower is better. Anything under 4-5 seconds is perfectly fine (though slow). Most servers should be under 1 second, even on slow connections. 30 - 40 msecs is not rare these days, but again, a high number here means it takes a longer time for the packet to get to the other end and be responded to. Large numbers are fine. You have to measure time against what you think is normal for that server. Your time of 253 msecs is normal and fine.

On all, your ping results look typical for a larger site, though we would need to see a larger set of them to be really sure.

coteyr
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  • Ow, nice explanation. I edited my post since using a VPN I can open the site. Also, I found some others having the same problem using IPV6. Maybe it is related. – Sigur Jun 18 '15 at 20:48