Performance testing ssh (was Re: question)

[Ed Sutter]

Yep, thanks, I've been running with WireShark...
(running it on the same machine as the client, so no need for mirroring 
here).
>
> Ed,
>
> I would also tcpdump all the network traffic during the test... using 
> a real hub or switch with port mirroring or vswitch promiscuous mode.
>
> At least then you could eliminate any lower level issues.
>
> Good luck.
>
> --
> http://www.realthought.net/
>
> El 26/04/2013 05:02, "Ed Sutter" <ed.sutter at alcatel-lucent.com 
> <mailto:ed.sutter at alcatel-lucent.com>> escribió:
>
>     Hi,
>     I have a modified version of the dropbear ssh server running in
>     a multitasking RTOS environment that is not POSIX compliant.
>     In almost all cases it is running perfectly...
>     I run load tests on it by just using a simple expect script
>     that spawns an ssh client and sends commands and expects
>     responses (in a loop).
>     If, within that loop, I occasionally (every ~30 minutes)
>     disconnect and reconnect then I can let that run *forever*
>     (haven't fully tested that).  :-(
>
>     The problem I run into is if I just make an initial connection
>     and put the script in a loop that simply keeps issuing commands
>     and responses (I never disconnect; just maintain the initial session).
>     After some unpredictable amount of time (usually it takes an hour or
>     more); having invoked a few thousand commands, suddenly everything
>     just stops.  The server is sitting in the select of the session_loop,
>     and the client (in the expect script) is just waiting for a response.
>
>     It seems like everything is where its supposed to be, but the client
>     is not able to send any characters to the server.  It appears that the
>     connection dropped; however, I'm fairly certain that it has not.
>
>     So, I apparently broke something; hence my question...
>
>     After the client/server transactions for key exchange,
>     login/password etc..
>     are complete and basically both sides are just passing encrypted
>     data back
>     and forth, is there any other periodic responsibility (on the
>     servers' part)
>     to issue any "keep-alive" type of commands (or something similar)
>     that I
>     have not implemented?
>
>     Thanks,
>     Ed
>