Learning Forum

[hpcadmin7]

Hi,

I manage an HPC environment (CentOS 7.6) that runs Fluent and LS-DYNA version R19. The license server is hosted in an outside Engineering department on campus.  The programs worked until the license server was changed (IP address/hostname change). I was informed to set ansyslmd.ini to the following port and hostnames:

SERVER=1055@licenseServerHostname
ANSYSLI_SERVERS=1055@licenseServerHostname

Running Fluent resulted in a license error:

   ANSYSLI_SERVERS: 1055@licenseserverhostname
   FLEXlm Servers: 1055@licenseserverhostname
   Could not make an SSL handshake with server    1055@licenseserverhostname

Same with ANSYS Structures:

   ******** UNEXPECTED ERROR - NETWORK TASK CONTROL INCONSISTENCY *****=
   **
   Please contact your ANSYS Sales Representative or ANSYS, Inc.

   ANSYS LICENSE MANAGER ERROR:
   Could not connect to any license server.

   The server is down or is not responsive.

   ANSYSLI_SERVERS: 1055@licenseServerHostname
   FLEXlm Servers: 1055@licenseServerHostname

The admin for the license server confirmed that the node accepts all incoming IP addresses. The HPC center/compute node also has no firewall rules that would block the connection from/to the license server on port 1055.

The compute node can ping the license server's IP). There is a proxy server that sits between the compute node and the license server. The license server is able to ping this proxy's IP address.

 

[hpcadmin7]

 

Also, running netcat on the compute node to contact the license server’s port 1055 succeeded:

   nc -zv licenseServerIpAddr 1055
   Ncat: Connected to licenseServerIpAddr:1055.
   Ncat: 0 bytes sent, 0 bytes received in 0.02 seconds.

The license server runs on Windows, and the administrator double checked to see that there are no firewalls to block the connection. Other Windows clients work in checking out the license. Our clients/compute nodes differ from those other clients because the compute nodes run CentOS 7.6.

Any ideas? Could it be a version difference issue? I’m puzzled because it seems like the network tests show full connectivity.

Thank you in advance.

 

 

[hpcadmin7]

 

I learned about the program “ansysli_util” that I can run on the client node to test for the license interaction. The tests below confirmed the problem being an SSL error, and not problems with general TCP/IP connectivity:

Command: 

ansysli_util -statli $PORT@$HOSTNAME
 

When I run the program by inputting  the correct license server hostname:port, I get the below (truncated). This SSL error is also seen in the Fluent error log above:

 

 Could not make an SSL handshake with server 1055@correcthostname.
                    System error: 0 "".

 

When I test by inputting the wrong port but right hostname:

 

Could not connect to license server: 22@correcthostname. Connection timed out while connecting to the server.

 

When I test by inputting the right port but wrong hostname:

 

                    Could not connect to license server: 1055@wronghostname. Host not found.

 

I searched the forums but couldn’t find possible solutions. 

 

[hpcadmin7]

The problem was fixed after following an idea from post, which talked about how older versions of ANSYS require different configuration compared to newer versions. The new license server had port 2325 closed. But because I was running an older version (2019), the client needed that port opened along with the ansymld.ini variable ANSYSLI_SERVERS set for that port. So, after the license server opened up that port, and after changing the client's ansyslmd.ini to the below, we can run Fluent and Structures again:

 SERVER=1055@licserverhostname
ANSYSLI_SERVERS=2325@licserverhostname

Running ansysli_util -statli $PORT@$HOSTNAME  was helpful as a quick test showing that the license interaction was good.