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SSH connection problem with an HP switch in ArubaOS

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  • 1.  SSH connection problem with an HP switch in ArubaOS

    Posted Apr 14, 2017 10:41 AM
     

    Hello,I have a problem with HP switch under ArubaOS.

    I try to connect by SSH on it, with Ansible (it is a platform that allows automate some tasks) for ping or to do some tasks, but it fails :

     

    10.44.23.212 | FAILED ! => {
       "changed": false,
       "failed": true
       "module_stderr": Connection to 10.44.23.212 closed by remote hosts.
         "module_stdout": "SSH command execution is not supported",
         "msg": "MODULE FAILURE",
         "rc": 0
    }

    Knowing that I can connect me to the switch by SSH with the prompt.

     

    Do I have to do any manipulations at the config level of the switch or do you think that it is a probleme with the platform that I use ?



  • 2.  RE: SSH connection problem with an HP switch in ArubaOS
    Best Answer

    Posted Apr 18, 2017 12:05 PM

    I believe this is a limitation (or one of the limitations) of the SSH server in ArubaOS. I ran into a similar interop issue when I tried to use a library that relies on an SSH session with two channels (iirc that was with the Perl Net::SSH library).

     

    Ansible probably just wants to execute a remote command, without requesting a full interactive SSH session. You can try something like this yourself:

     

    user@host:~$ ssh manager@testswitch "show ver"
    We'd like to keep you up to date about:
      * Software feature updates
      * New product announcements
      * Special events
    Please register your products now at:  www.hpe.com/networking/register
    
    
    manager@testswitch's password:
    SSH command execution is not supported.
    Connection to testswitch closed by remote host.
    user@host:~$

    and you'll see more of what's going on when you add the '-v' flag for verbose output:

    user@host:~$ ssh -v manager@testswitch "show ver"
    OpenSSH_5.9p1 Debian-5ubuntu1.9, OpenSSL 1.0.1 14 Mar 2012
    debug1: Reading configuration data /etc/ssh/ssh_config
    debug1: /etc/ssh/ssh_config line 19: Applying options for *
    debug1: Connecting to testswitch [172.31.133.29] port 22.
    debug1: Connection established.
    debug1: Remote protocol version 2.0, remote software version Mocana SSH 5.8
    debug1: no match: Mocana SSH 5.8
    debug1: Enabling compatibility mode for protocol 2.0
    debug1: Local version string SSH-2.0-OpenSSH_5.9p1 Debian-5ubuntu1.9
    debug1: SSH2_MSG_KEXINIT sent
    debug1: SSH2_MSG_KEXINIT received
    debug1: kex: server->client aes128-ctr hmac-md5 none
    debug1: kex: client->server aes128-ctr hmac-md5 none
    debug1: sending SSH2_MSG_KEXDH_INIT
    debug1: expecting SSH2_MSG_KEXDH_REPLY
    debug1: Server host key: RSA 12:ff:bc:13:f6:1a:92:be:f3:b9:2f:c0:41:62:6a:59
    debug1: Host 'testswitch' is known and matches the RSA host key.
    debug1: Found key in /home/user/.ssh/known_hosts:113
    debug1: ssh_rsa_verify: signature correct
    debug1: SSH2_MSG_NEWKEYS sent
    debug1: expecting SSH2_MSG_NEWKEYS
    debug1: SSH2_MSG_NEWKEYS received
    debug1: SSH2_MSG_SERVICE_REQUEST sent
    debug1: SSH2_MSG_SERVICE_ACCEPT received
    We'd like to keep you up to date about:
      * Software feature updates
      * New product announcements
      * Special events
    Please register your products now at:  www.hpe.com/networking/register
    
    
    debug1: Authentications that can continue: password
    debug1: Next authentication method: password
    manager@testswitch's password:
    debug1: Authentication succeeded (password).
    Authenticated to testswitch ([172.31.133.29]:22).
    debug1: channel 0: new [client-session]
    debug1: Entering interactive session.
    debug1: Sending environment.
    debug1: Sending env LANG = en_US.UTF-8
    debug1: Sending command: show ver
    debug1: client_input_channel_req: channel 0 rtype exit-status reply 0
    SSH command execution is not supported.
    debug1: channel 0: free: client-session, nchannels 1
    Connection to testswitch closed by remote host.
    Transferred: sent 1960, received 1752 bytes, in 0.2 seconds
    Bytes per second: sent 10312.5, received 9218.1
    debug1: Exit status 0

    Generally I wouldn't recommend using CLI interaction for automation tasks though, CLIs are designed for human interaction and not with automation in mind. In my experience, CLI based automation is more likely to break with software updates than eg SNMP based config changes. You could also consider using the (relatively new) REST API that's been added to ArubaOS, if the learning curve for SNMP is too steep.



  • 3.  RE: SSH connection problem with an HP switch in ArubaOS

    Posted Apr 20, 2017 02:51 AM

    Thanks for your reply. 

    I will see if it's possible with the REST api or if I can use SNMP to do backup with Ansible (I know that there is snmp modules to do task with ansible).


     



  • 4.  RE: SSH connection problem with an HP switch in ArubaOS

    Posted Apr 20, 2017 08:17 AM

    Let me know if you need some additional pointers or code examples for specific SNMP operations, such as config copying or small config changes.

     

    If your primary concern right now is fetching the configs, try these steps to simply fetch them using SFTP:

     

    1) Make sure that you can use key-based authentication to connect to the switch, if you haven't done so already. Configuration steps are in the Access Security Guide, eg see http://h22208.www2.hpe.com/eginfolib/networking/docs/switches/RA/15-18/5998-8151_ra_2620_asg/content/ch08s06.html.

     

    2) Create a small file with the SFTP commands that you want to execute. My example file "get_configs.sftp" just contains the commands to fetch running-config and startup-config from the switch and then terminates the SFTP session:

    get /cfg/running-config
    get /cfg/startup-config
    bye
    
    

    3) Use SFTP client in batch mode, supplying the command file that you just created: 'sftp -b get_configs.sftp username@switch'

     

    And to show that this works for me:

    user@host:~$ sftp -b get_configs.sftp manager@testswitch
    We'd like to keep you up to date about:
      * Software feature updates
      * New product announcements
      * Special events
    Please register your products now at:  www.hpe.com/networking/register
    
    
    sftp> get /cfg/running-config
    Fetching /cfg/running-config to running-config
    sftp> get /cfg/startup-config
    Fetching /cfg/startup-config to startup-config
    sftp> bye
    Connection to testswitch closed by remote host.
    user@host:~$