Gateway problems

PowerShell session fails when a Windows gateway with Cygwin SSH Server is used

Problem

PowerShell session fails when a Windows gateway with Cygwin SSH Server is used. Session sensor fails with the following message:

CTJTP1163E The following sessions cannot be established: (…) Failed to create PowerShell session: [10.23.45.7] Connecting to remote server failed 
with the following error message : WinRM cannot process the request. The 
following error occured while using Negotiate authentication: A specified 
logon session does not exist. It may already have been terminated (…)

Solution

Some of the Cygwin SSH servers handle the SSH session reuse incorrectly. As a result, remote SSH commands are run with permissions that are different than the required ones. To solve this problem, complete one of the following steps:

• Append the Cygwin SSH version to the com.collation.SshSessionReuseSuppressList property in the collation.properties file. To determine which version of Cygwin SSH you have, open the SessionSensor log file of the server that causes the discovery to fail, and look for the line that contains getSshVersion. For example:

  SessionSensor-10.23.45.7-[135,389,443,445,636,5985]INFO 
  session.Ssh2SessionClient - getSshVersion: from transport_, version is SSH- 2.0-OpenSSH_6.7.8

  In this case, the Cygwin SSH version is SSH-2.0-OpenSSH_6.7.8.
• Modify Cygwin SSH Server configuration so that the server is run by the same user that is used for the discovery.
• Modify the TADDM access list so that during discoveries the same user is used as when running Cygwin SSH Server.

Discovery fails when running a gateway on Windows Server 2012

Note: The following problem is not applicable to TADDM 7.3.0.2, or later.

Problem

Discovery fails when running a gatewayr on Windows Server 2012.

Solution

To run a gateway on Windows Server 2012, you must install Microsoft .NET Framework 3.5. The default version is 4.5. For more information about installing Microsoft .NET Framework 3.5, see http://technet.microsoft.com/en-us/library/hh831809.aspx#BKMK_FoD.

Also, check the version of the SSH server on the gateway and install the supported one. For more information about the supported software, see Windows gateways.

Session sensor ends with an error that the server cannot find a gateway for the target computer system

Problem

The session sensor ends with an error that the server cannot find a working gateway for a target computer system.

Solution

There are two possible causes for this problem:

• The gateway is not defined in the Discovery Management Console, the access list does not have the correct access list credentials or both. Ensure that the gateway is defined and the correct access list credentials are used.
• Add the following entry to the collation.properties, when you are using both an anchor and a gateway on the same system:

  com.collation.platform.session.GatewayForceSsh=true

  This entry specifies whether to force the gateway to act independently of the anchor. When the value is set to true, an SSH session is used to transfer traffic between the gateway and anchor rather than a local session.

When discovering multiple Windows servers, A Working gateway cannot be found error is displayed

Problem

When discovering a group of 10 or more Windows targets, some discoveries might end with the following error:

A Working gateway cannot be found

In addition, you might see an error like the following in the sensor log when using Cygwin:

SSH2EOFException: Server closed connection before sending identification

Solution

This problem might occur because Cygwin and Bitvise WinSSHD are configured out of the box to limit simultaneous connections using SSH. On a fast gateway and TADDM server, the SSH connections might exceed the out-of-the-box values configured for connections. It might help to configure some of the following properties, depending on your environment:

• For Bitvise WinSSHD, decrease the Accept delay value to 1 and the Login attempt delay value to 0.
• For Cygwin, change the MaxStartups value to at least 30. You might need to increase the MaxSessions value also.