From: Victor Cappuccio (vcappuccio@gmail.com)
Date: Sun Nov 04 2007 - 00:13:14 ART
Hi Chan, I do not have a couple of devices to test this, but I think I've
experienced this issue before, try this
http://www.cisco.com/univercd/cc/td/doc/product/software/ios123/123tcr/123ttsr/ter_l1gt.htm#wp1056778
in the router making the connection in line con place the session-timeout to
0 if you are connected to the router via de console.
Just my 2 cents
Victor.-
On 11/4/07, C Chan <cch.ccie@gmail.com> wrote:
>
> Dear Expert,
>
> Assume that I am using R2 to telnet R1. It is common that sudden TCP
> disconnection happens in the WAN cloud between R1 and R2. Whenever the
> disconnection happens, I found that it is difficult to get back R2
> terminal
> screen (already telnet to R1 and got halts). I have tried to use "ctrl-c",
> "ctrl-x", "ctrl-z", "ctrl-^" to break the session. None of them works.
>
> When I turn on "debug ip tcp trans" on R2 before sudden TCP disconnection
> happens. I found that the TCP session will retry 16 times before declaring
> session closed automatically. However, it already takes 7 mins before
> getting R2 terminal back on my control.
>
> Thanks for your advice in advance.
>
> R28_TS#2
> [Resuming connection 2 to r2 ... ]
> SENT -> ESTAB [41396 -> 10.0.0.1(23)]
> *Nov 3 13:05:43 UTC: TCP: tcb 66DE5D08 connection to 10.0.0.1:23, peer
> MSS
> 536, MSS is 536
> *Nov 3 13:05:43 UTC: TCB66DE5D08 connected to 10.0.0.1.23
> *Nov 3 13:07:47 UTC: TCP0: Data repacketized, seq 1979629618, sent 10
> byte
> *Nov 3 13:07:47 UTC: 155.1.23.2:41396 <---> 10.0.0.1:23 congestion
> window
> changes
> *Nov 3 13:07:47 UTC: cwnd from 573 to 536, ssthresh from 65535 to 1072
> *Nov 3 13:07:47 UTC: TCP0: timeout #1 - timeout is 2146 ms, seq
> 1979629618
> *Nov 3 13:07:49 UTC: TCP0: Data repacketized, seq 1979629618, sent 20
> byte
> *Nov 3 13:07:49 UTC: TCP0: timeout #2 - timeout is 4292 ms, seq
> 1979629618
> *Nov 3 13:07:54 UTC: TCP0: Data repacketized, seq 1979629618, sent 36
> byte
> *Nov 3 13:07:54 UTC: TCP0: timeout #3 - timeout is 8584 ms, seq
> 1979629618
> *Nov 3 13:08:02 UTC: TCP0: Data repacketized, seq 1979629618, sent 48
> byte
> *Nov 3 13:08:02 UTC: TCP0: timeout #4 - timeout is 17168 ms, seq
> 1979629618
> *Nov 3 13:08:20 UTC: TCP0: Data repacketized, seq 1979629618, sent 64
> byte
> *Nov 3 13:08:20 UTC: TCP0: timeout #5 - timeout is 34336 ms, seq
> 1979629618
> *Nov 3 13:08:54 UTC: TCP0: timeout #6 - timeout is 34336 ms, seq
> 1979629618
> *Nov 3 13:09:28 UTC: TCP0: timeout #7 - timeout is 34336 ms, seq
> 1979629618
> *Nov 3 13:10:03 UTC: TCP0: timeout #8 - timeout is 34336 ms, seq
> 1979629618
> *Nov 3 13:10:37 UTC: TCP0: timeout #9 - timeout is 34336 ms, seq
> 1979629618
> *Nov 3 13:11:11 UTC: TCP0: timeout #10 - timeout is 34336 ms, seq
> 1979629618
> *Nov 3 13:11:46 UTC: TCP0: timeout #11 - timeout is 34336 ms, seq
> 1979629618
> *Nov 3 13:12:20 UTC: TCP0: timeout #12 - timeout is 34336 ms, seq
> 1979629618
> *Nov 3 13:12:54 UTC: TCP0: timeout #13 - timeout is 34336 ms, seq
> 1979629618
> *Nov 3 13:13:29 UTC: TCP0: timeout #14 - timeout is 34336 ms, seq
> 1979629618
> *Nov 3 13:14:03 UTC: TCP0: timeout #15 - timeout is 34336 ms, seq
> 1979629618
> *Nov 3 13:14:37 UTC: TCP0: timeout #16 - timeout is 34336 ms, seq
> 1979629618
> [Connection to 10.0.0.1 closed by foreign host]
> R2#
> *Nov 3 13:24:18 UTC: TCP0: Data repacketized, seq 3363863064, sent 63
> byte
> *Nov 3 13:24:18 UTC: TCP0: state was ESTAB -> CLOSED [13562 -> 10.0.0.1
> (23)]
> *Nov 3 13:24:18 UTC: TCB 0x67139504 destroyed
>
> Regards,
> cch
>
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-- Victor Cappuccio www.vcappuccio.wordpress.com
This archive was generated by hypermail 2.1.4 : Sat Dec 01 2007 - 06:37:28 ART