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Hi!

From windows 2012 I am trying to telnet to destination on specific port and its not working. I can do telnet from win 7 win 2008 from the same network. I did capture on win 2012 and looks like the win 2012 is not sending ACK.

19452   0.000270000 5.730763000 SRC Dst 64569   25000   TCP 64569 > 25000 [SYN, ECN, CWR] Seq=0 Win=8192 Len=0 MSS=1460 WS=256 SACK_PERM=1  19452

29390   0.000100000 8.737071000 SRC Dst 64569   25000   TCP [TCP Retransmission] 64569 > 25000 [SYN, ECN, CWR] Seq=0 Win=8192 Len=0 MSS=1460 WS=256 SACK_PERM=1 29390

29753   0.000484000 8.849849000 DST SRC 25000   64569   TCP 25000 > 64569 [ACK] Seq=1 Ack=1 Win=32775 Len=0 29753

48941   0.000538000 14.734428000    SRC DST 64569   25000   TCP [TCP Retransmission] 64569 > 25000 [SYN] Seq=0 Win=8192 Len=0 MSS=1460 SACK_PERM=1  48941

49454   0.000033000 14.847287000    DST SRC 25000   64569   TCP [TCP Dup ACK 29753#1] 25000 > 64569 [ACK] Seq=1 Ack=1 Win=32775 Len=0   49454

I have changed the IP address to SRC and DST

Src = windows 2012 from where i am doing telnet dst 25000

Anyone can help.

Thanks

asked 11 Apr '14, 07:53

capricorn800's gravatar image

capricorn800
16224
accept rate: 0%

edited 14 Apr '14, 03:00

grahamb's gravatar image

grahamb ♦
19.8k330206


You can try disabling ECN on windows 2012 by issuing

netsh interface tcp set global ecncapability=disabled

See http://serverfault.com/questions/526377/

permanent link

answered 11 Apr '14, 10:51

mrEEde's gravatar image

mrEEde
3.9k152270
accept rate: 20%

Thanks the answer helped and fixed the problem.

(14 Apr '14, 02:04) capricorn800

@capricorn800

If an answer has solved your issue, please accept the answer for the benefit of other users by clicking the checkmark icon next to the answer. Please read the FAQ for more information.

(14 Apr '14, 03:00) grahamb ♦
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question asked: 11 Apr '14, 07:53

question was seen: 4,415 times

last updated: 14 Apr '14, 03:00

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