RE: lost tcp/ip connections

2004-02-02 Thread JD
Donnie,

You are probably aware of this, but still...
To avoid loosing sessions due to network problems, I screen them.
I added exec screen -xRR -T vt100 to my .profile script.
Of course you should change the options to suit your needs.
Now whenever I get disconnected, and then reconnect - I do not loose
anything.
It works for me, and helped me run some lengthy reports remotely.
BTW, I use ssh instead of telnet.

JD


On Fri, 30 Jan 2004, Donnie Jacobs wrote:

 Hi Robert,

 Thanks for the information...I've tried what you suggested. I modified
 the tcp_keepalive_time, tcp_keepalive_intvl, and tcp_keepalive_probe
 settings. Below is how they're currently set

 [EMAIL PROTECTED] /root]# more /proc/sys/net/ipv4/tcp_keepalive_*
 ::
 /proc/sys/net/ipv4/tcp_keepalive_intvl
 ::
 30
 ::
 /proc/sys/net/ipv4/tcp_keepalive_probes
 ::
 5
 ::
 /proc/sys/net/ipv4/tcp_keepalive_time
 ::
 60


 I set these up in the init script and rebooted the machine, verified
 that they were still in place and then did the whole connect / unplug
 cable / reconnect cable bit.


 Based on these settings, I would have thought that after 60 seconds of
 inactivity, that I would get a max of 5 probes at 30 second intervals,
 and if no response was received, the connection would die.  That should
 be a total of...60 seconds + (30 seconds * 5 tries = 150) = 210 seconds
 or just under 4 minutes...


 However, I've been back in for about 15 minutes now, and still see both
 logins when I do the who

 Did I miss something?

 Thanks,

 Donnie Jacobs
 Sr Developer
 GC Services LP
 713-776-6503
 [EMAIL PROTECTED]

 -Original Message-
 From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED]
 Behalf Of Robert Porter
 Sent: Friday, January 30, 2004 1:19 PM
 To: [EMAIL PROTECTED]
 Subject: Re: lost tcp/ip connections

 That's a TCP/IP keepalive timeout...
 The setting is viewable and changable - It should be found at
 /proc/sys/net/ipv4/tcp_keepalive_time
 Changing it won't survive a reboot though. You'll either need to change
 it every time or do so in a script at init.

 rfp



  [EMAIL PROTECTED] 01/30/04 01:12PM 
 Hello all,

 I'm wondering if there's a way within Linux to detect when a tcp/ip
 connection is lost. Here's the scenario...

 I telnet to my linux machine from my PC. I then disconnect my Ethernet
 cable  (simulating a network failure, loss of broadband service, etc..)
 Then I reconnect my Ethernet cable and telnet into the linux machine
 again.

 If I do a who command, I see the old connection as well as my current
 connection.

 Running RedHat Linux 8, universe 10.0.13

 I've tried several variations of netstat, who, etc...to try and identify
 these stranded connections, with no luck.


 Any ideas?

 Thanks,
 Donnie Jacobs
 Sr Developer
 GC Services LP
 713-776-6503
 [EMAIL PROTECTED]

 ___
 u2-users mailing list
 [EMAIL PROTECTED]
 http://www.oliver.com/mailman/listinfo/u2-users

___
u2-users mailing list
[EMAIL PROTECTED]
http://www.oliver.com/mailman/listinfo/u2-users


RE: lost tcp/ip connections

2004-02-02 Thread JD

It's available for aix.

Please check:
http://www-1.ibm.com/servers/aix/products/aixos/linux/rpmgroups.html

JD


On Mon, 2 Feb 2004 [EMAIL PROTECTED] wrote:

 What is 'screen'?  I don't find it on AIX.  Is it a Linux thing?  If it
 does what I think you are implying, it would be a wonderful thing.

 Thanks


 Harman Armstrong
 [EMAIL PROTECTED]





 JD [EMAIL PROTECTED]
 Sent by: [EMAIL PROTECTED]
 02/02/2004 01:22 PM
 Please respond to U2 Users Discussion List


 To: U2 Users Discussion List [EMAIL PROTECTED]
 cc:
 Subject:RE: lost tcp/ip connections


 Donnie,

 You are probably aware of this, but still...
 To avoid loosing sessions due to network problems, I screen them.
 I added exec screen -xRR -T vt100 to my .profile script snip




 ___
 u2-users mailing list
 [EMAIL PROTECTED]
 http://www.oliver.com/mailman/listinfo/u2-users

___
u2-users mailing list
[EMAIL PROTECTED]
http://www.oliver.com/mailman/listinfo/u2-users


RE: lost tcp/ip connections

2004-01-30 Thread Donnie Jacobs









There is a
“-n” option on the telnetd command that says “disable tcp keep-alives” The
default is for the keep-alives to be enabled.



If I look
at the /etc/xinetd.d/telnet file, I see the following : 



[EMAIL PROTECTED]
/root]# cat /etc/xinetd.d/telnet

# default:
on

#
description: The telnet server serves telnet sessions; it uses \

#
unencrypted username/password pairs for authentication.

service
telnet

{


flags =
REUSE

 socket_type = stream


wait
= no


user
= root


server =
/usr/sbin/in.telnetd


log_on_failure += USERID


disable = no

}



based on
the value of the “server” entry, it doesn’t appear that the “-n” option should
be coming into play.



Donnie Jacobs

Sr Developer

GC Services LP

713-776-6503

[EMAIL PROTECTED]



-Original
Message-
From: [EMAIL PROTECTED]
[mailto:[EMAIL PROTECTED]On Behalf
Of Robert Porter
Sent: Friday, January 30, 2004
3:09 PM
To: [EMAIL PROTECTED]
Subject: RE: lost tcp/ip
connections



Are you logging in by
telnet or ssh? I'm wondering if your daemon is doing
something funny with keepalive for some reason. Some telnetd's do have an
option to turn it off. Try a man in.telnetd or just man telnetd to
see if that's a possibility.



rfp



 [EMAIL PROTECTED] 01/30/04 02:37PM 

Hi Robert,



Thanks for the information…I’ve tried what you suggested. I
modified the tcp_keepalive_time, tcp_keepalive_intvl, and tcp_keepalive_probe
settings. Below is how they’re currently set….



[EMAIL PROTECTED] /root]# more
/proc/sys/net/ipv4/tcp_keepalive_*

::

/proc/sys/net/ipv4/tcp_keepalive_intvl

::

30

::

/proc/sys/net/ipv4/tcp_keepalive_probes

::

5

::

/proc/sys/net/ipv4/tcp_keepalive_time

::

60





I set these up in the init script and rebooted the machine,
verified that they were still in place and then did the whole connect / unplug
cable / reconnect cable bit.





Based on these settings, I would have thought that after 60
seconds of inactivity, that I would get a max of 5 probes at 30 second
intervals, and if no response was received, the connection would die. That should be a total of…60 seconds +
(30 seconds * 5 tries = 150) = 210 seconds or just under 4 minutes…





However, I’ve been back in for about 15 minutes now, and
still see both logins when I do the who….



Did I miss something?



Thanks,



Donnie
Jacobs

Sr Developer

GC Services LP

713-776-6503

[EMAIL PROTECTED]



-Original Message-
From: [EMAIL PROTECTED]
[mailto:[EMAIL PROTECTED]On Behalf
Of Robert Porter
Sent: Friday, January 30, 2004
1:19 PM
To: [EMAIL PROTECTED]
Subject: Re: lost tcp/ip
connections



That's a TCP/IP
keepalive timeout... 

The setting is viewable and changable - It
should be found at /proc/sys/net/ipv4/tcp_keepalive_time

Changing it won't survive a reboot though.
You'll either need to change it every time or do so in a script at init.



rfp





 [EMAIL PROTECTED] 01/30/04 01:12PM 
Hello all,

I'm wondering if there's a way within Linux to detect when a tcp/ip connection
is lost. Here's the scenario...

I telnet to my linux machine from my PC. I then disconnect my Ethernet cable
(simulating a network failure, loss of broadband service, etc..) Then I
reconnect my Ethernet cable and telnet into the linux machine again.

If I do a who command, I see the old connection as well as my
current connection. 

Running RedHat Linux 8, universe 10.0.13

I've tried several variations of netstat, who, etc...to try and identify these
stranded connections, with no luck.


Any ideas?

Thanks,
Donnie Jacobs
Sr Developer
GC Services LP
713-776-6503
[EMAIL PROTECTED]

___
u2-users mailing list
[EMAIL PROTECTED]
http://www.oliver.com/mailman/listinfo/u2-users






___
u2-users mailing list
[EMAIL PROTECTED]
http://www.oliver.com/mailman/listinfo/u2-users