Your browser does not allow storing cookies. We recommend enabling them.

SSH Tectia 
PreviousNextUp[Contents] [Index]

    About This Document >>
    Installing SSH Tectia Server for IBM z/OS >>
    Using SSH Tectia Server for IBM z/OS >>
    Configuring the Server >>
        Configuration Files >>
            Editing Configuration Files
            Command-Line Options
            Recommended Algorithms for Mainframe Environment
            Crypto Hardware Support
            Configuration Options in Load-Balanced Environments
            Running SSH Tectia and OpenSSH in a z/OS Environment
        Subconfigurations >>
        Ciphers and MACs
        Configuring Root Logins
        Restricting User Logins
        Auditing >>
        Securing the Server >>
        Default sshd2_config Configuration File
        Default ssh_certd_config Configuration File
    Configuring the Client >>
    Authentication >>
    Troubleshooting SSH Tectia Server for IBM z/OS >>
    Examples of Use >>
    Man Pages >>
    Log Messages >>

Configuration Options in Load-Balanced Environments

To tunnel traffic between clients and balanced hosts, the SSH traffic needs to be balanced on the load balancer instead of the port traffic.

Example scenario:

Client machine needs to reach which is load-balanced by three machines (,, and The load balancer may forward the client's request to either machine on the port the daemon is listening on. The first request may go to and the second request may go to If the client's request goes to and is forwarded to, the SSH tunnel will terminate on the load balancer.


  • Client has SSH Tectia Client (or Connector) installed.
  • Balanced hosts have SSH Tectia Servers installed.
  • The load balancer forwards the clients' port 22 requests to balanced hosts.
  • In order for tunneling to work, all the balanced hosts must use the same port, for example 8080 (now 8080, 8000 and 9000).
  • The clients create connections to with local tunnels 80:
  • The load balancer forwards the traffic to one of the balanced hosts and a local listener is created on Windows.
  • Now, when the SSH connection is created between the client and the balanced host, the client uses its application and connects to localhost:80. Traffic is forwarded to the SSH connection and to the balanced host.

If this is not possible, there are two choices:

  1. You can end the tunnel at the load balancer. In this case, the traffic between the client ( and the load balancer ( is encrypted and the traffic between the balancer and the balanced hosts is not encrypted. Therefore you should create an SSH connection from the client to the balancer with a local tunnel 80:
  2. Another possibility is to install SSH Tectia Servers to balanced hosts and create the direct tunnels between the client and the balanced hosts. In this case, a load balancer cannot be used, but the balancing needs to be done in a different way, for example by using a round-robin DNS.

PreviousNextUp[Contents] [Index]

[ Contact Information | Support | Feedback | SSH Home Page | SSH Products ]

Copyright © 2006 SSH Communications Security Corp.
This software is protected by international copyright laws. All rights reserved.
Copyright Notice




What to read next:

  • Reduce Secure Shell risk. Get to know the NIST 7966.

    The NISTIR 7966 guideline from the Computer Security Division of NIST is a direct call to action for organizations regardless of industry and is a mandate for the US Federal government.
    Download now
  • ISACA Practitioner Guide for SSH

    With contributions from practitioners, specialists and SSH.COM experts, the ISACA “SSH: Practitioner Considerations” guide is vital best practice from the compliance and audit community.
    Download now