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I’ve set up a lone server connected via LAN to a router. It used to work fine, but something happened and messed up my Network settings.

Now after re-setting up the lan connection to the gateway I can only open some sites from the server. The sites I can’t open - I get using the Wireshark software this message: 4679 6697.004581 TCP 66 descent > http [SYN] Seq=0 Win=65535 Len=0 MSS=1460 WS=4 SACK_PERM=1 Which goes out 3 times and then nothing; my explorer just fails to open the page. So 3 times it sends the [SYN] and do not get a reply [SYN, ACK]. Can anyone give me some help? Please?

asked 17 May '12, 05:11

JosephW's gravatar image

accept rate: 0%

Can you ping the remote host? What happens if you telnet to port 80 on Can you get to any other internet hosts from this system?

First thing to do: check your firewall settings & confirm source/destination rules permit this traffic.

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answered 17 May '12, 08:25

Labnuke's gravatar image

accept rate: 0%

Thank you Labnuke for helping. Both pinging and telnet fails to all external sites, but I can ping and connect normally to the router The strange thing is that I can connect to some sites out there through the web browser.

(17 May '12, 11:10) JosephW

(I converted your "answer" to a "comment", that makes it easier for people to follow the discussion, please see the FAQ)

Then maybe your browser is using a proxy server and your router/FW is configured to not allow direct access to the Internet? Sounds like you are on a network controlled by someone else and the security policy has been tightened...

(17 May '12, 11:17) SYN-bit ♦♦

Well, I can neither connect to on port 80 nor can I ping it. So, the host might just be down, filtered by a packetfilter, or the whole net is not reachable right now. So, it's probably not your environment (local firewall) but the remote host, which possibly explains why you can connect to other hosts.


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answered 17 May '12, 14:26

Kurt%20Knochner's gravatar image

Kurt Knochner ♦
accept rate: 15%

Thanks Kurt, That was just a random IP; the problem is consistent (no reply) to all external ips (both with pining and telnet), BUT I can get through to some sites through my browser and I did clear my local web copies. So - some (few) sites work and most not and none with pining or telnet. I thought this would be a brainteaser even for you fundies. Joe

(17 May '12, 23:36) JosephW

(Joseph, please use "add comment" instead of "your answer" to respond to to a given answer. I converted your answer to a comment again)

(17 May '12, 23:50) SYN-bit ♦♦

Did you check the comment of SYN-bit (Proxies, Firewalls, etc.)?

(18 May '12, 01:42) Kurt Knochner ♦
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question asked: 17 May '12, 05:11

question was seen: 5,777 times

last updated: 18 May '12, 01:42

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