Cannot Connect to Intel® Flexlm* License Server Due to Firewall

Published: 07/04/2017  

Last Updated: 07/03/2017

By Yuan Chen


License check-out received error on Client system:

 INTEL: Cannot connect to license server system. (-15,570:115 "Operation now in progress")

User could telnet to server by server port: 28518. Server port: 28518 was opened in firewall.

Root Cause

When Intel(R) Flexlm license server starts, there are two server daemon running:

One is FlexNet Publisher* license server daemon, which used default 28518 port or the one set in SERVER line of the license file.

The other one is Intel(R) Software License Manager Vendor Daemon, which used TCP/IP port number specified on the VENDOR line of the license file. Normally this number is omitted. You may find the actual number from the server log. Depending on your operating system, the server log files are located on Windows*: <install drive>:\program files\common files\intel\flexlm\iflexlmlog.txt, or Linux* or OS*: <install location of servers>/lmgrd.log. You may find lines like followings from the log file:

... (INTEL) (@INTEL-SLOG@) === Network Info ===
... (INTEL) (@INTEL-SLOG@) Socket interface: IPV4
... (INTEL) (@INTEL-SLOG@) Listening port: 49163
... (INTEL) (@INTEL-SLOG@) Daemon select timeout (in seconds):

In this example, listening port 49163 is the default TCP/IP port for Intel VENDOR Daemon.

Because the later listening port: 49163 was not opened in Firewall, we cannot connect to the Vendor daemon and received error during license check-out on Client machines.


To connect to license server with Firewall enabled, you must add exceptions to open both listening ports of FlexNet Publisher* license server daemon and Intel(R) Software License Manager Vendor Daemon. In this case, opening port 49163 besides 28518 resolved the problem.

Intel’s FLEXlm specifies two ports:

1. SERVER host_name host_id port1 -- This one is specified in the product license for 28518)

2. VENDOR INTEL port=port2 -- Usually we specify port1 to 28518 and port2 is omitted (then system will choose one randomly).

However, you may specify port2 to a fixed value and open that port too on the firewall.

Product and Performance Information


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