in reply to Net::OpenSSH Multiple Commands - Session Destroyed

It seems that the SSH server is closing the connection after the first request. It may be a limitation of the device you are connecting to (unfortunately it is not to unusual to find defective SSH implementations in network devices and other embedded systems).

Just to be sure that this is the problem, ask the module to run the master ssh client in verbose mode: 

$ssh = Net::OpenSSH->new($host_ip, user => $user, password => $passwor
+d, master_opts => '-vv');

[download]
Also, add an error check after the capture call: 
my @output = $ssh->capture($_);
if ($ssh->error) {
  print STDERR "capture failed: " . $ssh->error;
}
else {
  print @output, "\n";
}

[download]

Replies are listed 'Best First'.
Re^2: Net::OpenSSH Multiple Commands - Session Destroyed
by Anonymous Monk on Mar 17, 2011 at 16:04 UTC
    Thank you for the quick feedback. I did what you suggested and the output is posted below. 
    
Executing subroutine ssh_to_ip
OpenSSH_5.5p1 Debian-4ubuntu5, OpenSSL 0.9.8o 01 Jun 2010
debug1: Reading configuration data /etc/ssh/ssh_config
debug1: Applying options for *
debug2: ssh_connect: needpriv 0
debug1: Connecting to 10.250.10.100 [10.250.10.100] port 22.
debug1: Connection established.
debug1: identity file /home/tmcurti/.ssh/id_rsa type -1
debug1: identity file /home/tmcurti/.ssh/id_rsa-cert type -1
debug1: identity file /home/tmcurti/.ssh/id_dsa type -1
debug1: identity file /home/tmcurti/.ssh/id_dsa-cert type -1
debug1: Remote protocol version 1.99, remote software version Cisco-1.
+25
debug1: no match: Cisco-1.25
debug1: Enabling compatibility mode for protocol 2.0
debug1: Local version string SSH-2.0-OpenSSH_5.5p1 Debian-4ubuntu5
debug2: fd 3 setting O_NONBLOCK
debug1: SSH2_MSG_KEXINIT sent
debug1: SSH2_MSG_KEXINIT received
debug2: kex_parse_kexinit: diffie-hellman-group-exchange-sha256,diffie
+-hellman-group-exchange-sha1,diffie-hellman-group14-sha1,diffie-hellm
+an-group1-sha1
debug2: kex_parse_kexinit: ssh-rsa-cert-v00@openssh.com,ssh-dss-cert-v
+00@openssh.com,ssh-rsa,ssh-dss
debug2: kex_parse_kexinit: aes128-ctr,aes192-ctr,aes256-ctr,arcfour256
+,arcfour128,aes128-cbc,3des-cbc,blowfish-cbc,cast128-cbc,aes192-cbc,a
+es256-cbc,arcfour,rijndael-cbc@lysator.liu.se
debug2: kex_parse_kexinit: aes128-ctr,aes192-ctr,aes256-ctr,arcfour256
+,arcfour128,aes128-cbc,3des-cbc,blowfish-cbc,cast128-cbc,aes192-cbc,a
+es256-cbc,arcfour,rijndael-cbc@lysator.liu.se
debug2: kex_parse_kexinit: hmac-md5,hmac-sha1,umac-64@openssh.com,hmac
+-ripemd160,hmac-ripemd160@openssh.com,hmac-sha1-96,hmac-md5-96
debug2: kex_parse_kexinit: hmac-md5,hmac-sha1,umac-64@openssh.com,hmac
+-ripemd160,hmac-ripemd160@openssh.com,hmac-sha1-96,hmac-md5-96
debug2: kex_parse_kexinit: none,zlib@openssh.com,zlib
debug2: kex_parse_kexinit: none,zlib@openssh.com,zlib
debug2: kex_parse_kexinit: 
debug2: kex_parse_kexinit: 
debug2: kex_parse_kexinit: first_kex_follows 0 
debug2: kex_parse_kexinit: reserved 0 
debug2: kex_parse_kexinit: diffie-hellman-group1-sha1
debug2: kex_parse_kexinit: ssh-rsa
debug2: kex_parse_kexinit: aes128-cbc,3des-cbc,aes192-cbc,aes256-cbc
debug2: kex_parse_kexinit: aes128-cbc,3des-cbc,aes192-cbc,aes256-cbc
debug2: kex_parse_kexinit: hmac-sha1,hmac-sha1-96,hmac-md5,hmac-md5-96
debug2: kex_parse_kexinit: hmac-sha1,hmac-sha1-96,hmac-md5,hmac-md5-96
debug2: kex_parse_kexinit: none
debug2: kex_parse_kexinit: none
debug2: kex_parse_kexinit: 
debug2: kex_parse_kexinit: 
debug2: kex_parse_kexinit: first_kex_follows 0 
debug2: kex_parse_kexinit: reserved 0 
debug2: mac_setup: found hmac-md5
debug1: kex: server->client aes128-cbc hmac-md5 none
debug2: mac_setup: found hmac-md5
debug1: kex: client->server aes128-cbc hmac-md5 none
debug2: dh_gen_key: priv key bits set: 124/256
debug2: bits set: 492/1024
debug1: sending SSH2_MSG_KEXDH_INIT
debug1: expecting SSH2_MSG_KEXDH_REPLY
debug1: Host '10.250.10.100' is known and matches the RSA host key.
debug1: Found key in /home/tmcurti/.ssh/known_hosts:5
debug2: bits set: 506/1024
debug1: ssh_rsa_verify: signature correct
debug2: kex_derive_keys
debug2: set_newkeys: mode 1
debug1: SSH2_MSG_NEWKEYS sent
debug1: expecting SSH2_MSG_NEWKEYS
debug2: set_newkeys: mode 0
debug1: SSH2_MSG_NEWKEYS received
debug1: Roaming not allowed by server
debug1: SSH2_MSG_SERVICE_REQUEST sent
debug2: service_accept: ssh-userauth
debug1: SSH2_MSG_SERVICE_ACCEPT received
debug2: key: /home/tmcurti/.ssh/id_rsa ((nil))
debug2: key: /home/tmcurti/.ssh/id_dsa ((nil))
debug1: Authentications that can continue: keyboard-interactive,passwo
+rd
debug1: Next authentication method: keyboard-interactive
debug2: userauth_kbdint
debug2: we sent a keyboard-interactive packet, wait for reply
debug2: input_userauth_info_req
debug2: input_userauth_info_req: num_prompts 1
debug1: Authentication succeeded (keyboard-interactive).
debug1: setting up multiplex master socket
debug2: fd 4 setting O_NONBLOCK
debug1: channel 0: new [/home/tmcurti/.libnet-openssh-perl/cisco-10.25
+0.10.100-2449-484163]
debug1: Entering interactive session.
debug1: multiplexing control connection
debug2: fd 5 setting O_NONBLOCK
debug1: channel 1: new [mux-control]
debug2: process_mux_master_hello: channel 1 slave version 4
debug2: process_mux_alive_check: channel 1: alive check
debug2: channel 1: ctl read<=0 rfd 5 len 0
debug2: channel 1: read failed
debug2: channel 1: close_read
debug2: channel 1: input open -> drain
debug2: channel 1: ibuf empty
debug2: channel 1: input drain -> closed
debug2: channel 1: rcvd close
debug2: channel 1: output open -> drain
debug2: channel 1: obuf empty
debug2: channel 1: close_write
debug2: channel 1: output drain -> closed
debug2: channel 1: is dead (local)
debug2: channel 1: gc: notify user
debug2: channel 1: gc: user detached
debug2: channel 1: is dead (local)
debug2: channel 1: garbage collecting
debug1: channel 1: free: mux-control, nchannels 2

Opening command file cmd.txt
Executing command show run | inc nterface.*5 on device 10.250.10.100


Executing command show ver | inc uptime on device 10.250.10.100


Attempting to execute command show run | inc nterface.*5 on host 10.25
+0.10.100debug1: multiplexing control connection
debug2: fd 5 setting O_NONBLOCK
debug1: channel 1: new [mux-control]
debug2: process_mux_master_hello: channel 1 slave version 4
debug2: process_mux_alive_check: channel 1: alive check
debug2: process_mux_new_session: channel 1: request tty 0, X 0, agent 
+0, subsys 0, term "xterm", cmd "show run | inc nterface.*5", env 1
debug2: fd 7 setting O_NONBLOCK
debug1: channel 2: new [client-session]
debug2: process_mux_new_session: channel_new: 2 linked to control chan
+nel 1
debug2: channel 2: send open
debug2: callback start
debug2: client_session2_setup: id 2
debug1: Sending environment.
debug1: Sending env LANG = en_US.utf8
debug2: channel 2: request env confirm 0
debug1: Sending command: show run | inc nterface.*5
debug2: channel 2: request exec confirm 1
debug2: callback done
debug2: channel 2: open confirm rwindow 1024 rmax 4096
debug2: channel_input_status_confirm: type 99 id 2
debug2: exec request accepted on channel 2
debug1: client_input_channel_req: channel 2 rtype exit-status reply 0
debug2: channel 2: rcvd eof
debug2: channel 2: output open -> drain
debug2: channel 2: obuf empty
debug2: channel 2: close_write
debug2: channel 2: output drain -> closed
debug2: channel 2: rcvd close
debug2: channel 2: close_read
debug2: channel 2: input open -> closed
debug2: channel 2: almost dead
debug2: channel 2: gc: notify user
debug2: channel 1: rcvd close
debug2: channel 1: output open -> drain
debug2: channel 1: close_read
debug2: channel 1: input open -> closed
debug2: channel 2: gc: user detached
debug2: channel 2: send close
debug2: channel 2: is dead
debug2: channel 2: garbage collecting
debug1: channel 2: free: client-session, nchannels 3
debug1: channel 0: free: /home/tmcurti/.libnet-openssh-perl/cisco-10.2
+50.10.100-2449-484163, nchannels 2
debug1: channel 1: free: mux-control, nchannels 1
Connection to 10.250.10.100 closed by remote host.
Transferred: sent 1456, received 1256 bytes, in 1.2 seconds
Bytes per second: sent 1178.8, received 1016.9
debug1: Exit status -1
7
capture failed: master ssh connection brokenAttempting to execute comm
+and show ver | inc uptime on host 10.250.10.100

    [download]
    I see the master connection is broken but do not understand from the output why it was broken. Any ideas?
[reply]
[d/l]
      It seems that the SSH server on your particular device is not able to handle several requests over the same connection.

      I can think of two workarounds for that:

      1. Open a new connection for every request
      2. Run a full interactive session on the server and use Expect to drive it (you can also try with Net::SSH::Expect or any of the other modules targeting specific Cisco devices).
[reply]

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