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What does this error mean?


Hello. When I want to run Telegram on my Windows OS, Telegram Can't connect to the internet. I use Wireshark for Capture it and Please see the Attachment and let me know your idea.

Thank you.alt text

asked 26 Jul '15, 07:53

hack3rcon's gravatar image

accept rate: 0%

It means that the RST Bit is set and this leads to a session termination. But the root cause, why the RST Bit is set here can't be seen at this screenshot. Maybe it is application related.

(26 Jul '15, 10:34) Christian_R

Could you provide us the whole traced session at dropbox or cloudshark?

(26 Jul '15, 11:41) Christian_R
(26 Jul '15, 22:57) hack3rcon

I can't see any RST Packet in the trace. But also I can't see any syn/ack packet in the trace. Maybe a firewall rule blocks the syn. Can you ping these addreses?

(27 Jul '15, 03:43) Christian_R

I ping the addresses and the result is :

What is your idea?

(27 Jul '15, 05:33) hack3rcon

One Answer:


In the context of you trying to reach a server on TCP port 445, based on the relative sequence number it looks like the application is running and some data has been exchanged, but very early on the server is abruptly killing the TCP session, likely due to application-level error.

Note, I'm assuming that packet came from the server based on the source mac being Cisco and the destination being more likely to be a PC. That and the source port is in the well-known range, so likely the service port reached by the client.

Also note, a 'reset' is a warning because it MIGHT be a problem. Some applications are just written such that they kill TCP sessions this way in normal conditions.

answered 26 Jul '15, 11:22

Quadratic's gravatar image

accept rate: 13%

edited 26 Jul '15, 11:23

I use a TMG Server and this problem occur on clients. My TMG server run Telegram without any problem.In TMG I use some rules and the PCs that want to use Telegram are NAT (Use a TMG rule that let them connect to internet directly). This problem suddenly happened :(.

(26 Jul '15, 11:40) hack3rcon