NCP connections and Watchdog under OES Linux

A customer of my complained that after migrating from Novell Netware 6.5 to OES2 Linux, the users complained that sometimes the loose their connection with a specific server.

After a trace (how to do show look here) I saw that if a users doesn’t uses a server for more than a hour his connection gets broken. If a users wants to for example get a file list of the specific server the get a connection broken error. If the click OK and the drive again the file list appears. The trace shows that after the connection broken error the Novell Client does a reset of the TCP connection and does a automatic user authentication to the server.
If you wait more than 2 hours the server sends a Keep-Alive packet to the workstation to see if the workstation is still available.
But why does the connection gets broken after a hour?? This was due a firewall that was between the workstation and server. This firewall (Cisco ASA) resets a TCP connection that isn’t used over a hour. They told me this is default.

The solution was to enable watchdog for OES2. Watchdog is a method to see if a workstation is still available. If you go to Remote Manager | Manage NCP Services | Manage Server you can define the option FIRST_WATCHDOG_PACKET. Default this option is 0, the value you define here is the time in minutes that the servers sends his first WATCHDOG packet to the workstation. After that the server will send every minute a WATCHDOG packet to the workstation to see if it’s still available.
I set mine to 50 minutes.

Here you can find information on setting for OES.

About Michael
Michael Wilmsen is a VMware training/consultant (no specific order) with more than 15 years in the IT industry. Main focus is VMware vSphere, Horizon View and Site Recovery Manager with a deepdive to performance. Michael is VCDX 210, VCAP 4/5 certified, has been rewarded with the vExpert title from 2011, is a PernixPro, Nutanix Tech Champion and a Nutanix Platform Professional.

4 Comments to “NCP connections and Watchdog under OES Linux”

  1. By Robert Jones, July 23, 2009 @ 21:23

    Thanks for your article. Novell says nothing about this, it has been plaguing us since we moved to SLES a month ago. I was beginning to think that the error “The specified network name is no longer available.” would cause us to have to go back to NetWare.

    I will be able to sleep well tonight.

    Thanks,
    Rob

  2. By Robert Jones, July 23, 2009 @ 21:23

    Thanks for your article. Novell says nothing about this, it has been plaguing us since we moved to SLES a month ago. I was beginning to think that the error “The specified network name is no longer available.” would cause us to have to go back to NetWare.

    I will be able to sleep well tonight.

    Thanks,
    Rob

  3. By Mabelle Kopas, November 21, 2010 @ 19:47

    Very well written information. It will be useful to anyone who usess it, including myself. Keep doing what you are doing – for sure i will check out more posts.

  4. By Mabelle Kopas, November 21, 2010 @ 19:47

    Very well written information. It will be useful to anyone who usess it, including myself. Keep doing what you are doing – for sure i will check out more posts.

RSS feed for comments on this post. TrackBack URI

Leave a Reply

You must be logged in to post a comment.