In the Arc10 Q&A for the 2011 user conference it says a performance gain may be realized by hardcoding the license manager to port 27000, and then instructing the firewall and Windows Defender to ignore that port.

That same doc references the online help for the specifics of how to implement that on the license manager server, namely edit services.txt to look like the below (the trailing numbers on first two lines used to blank):

SERVER this_host ANY 27000
FEATURE ACT ARCGIS 1 permanent 1 7ED49106D630

This is all well and good to this point, but I'm confused about what is happening with the server port and the vendor ports. Which way does the communication flow go? If the ArcGIS Vendor port is hardcoded, then does every client need to be updated to explicitly match that port? (e.g. do I have to visit every client machine and set their ArcGIS Desktop Adminstrator to use port 1234? or is it 27000?) Do I set the firewall to ignore one port or both ports? in or out? And is #1234 actually a safe number, or range of numbers?

2 Answers 2


I ended up contacting tech support over this one, who gave me an accurate but hard to understand answer. I took their words and turned into a graphic, which I then verified with them I correctly understood, and am now sharing with you:

Assuming a services.txt like the one in the above:

the server firewall should allow inbound connections on 27000 and outbound connections for 1234.

The arcgis desktop clients should allow outbound connections on 27000 and inbound connections for 1234.

And whatever you do, don't use 27000-27009 for the vendor daemon. My tech support rep suggested something in the 4000 range for the vendor daemon and client ports (1234 happens to be used by the popular VLC Media Player). I also found this handy list on wikipedia of tcp ports in common use.

Here's the cheesy graphic:

schematic of firewall ports needed for Arcgis license manager

Thank you Max S. of Esri Canada Tech Support.

  • Agree with the graph - nice way to understand the issues - other products (AutoCAD) use ports 27000-27009 so your correct and stay clear of them.
    – Mapperz
    Oct 6, 2011 at 13:41

So close, but so far. Trying an installation of my own, you had me going, until it did not work. Read the ArcGIS documentation again, and it states the vendor daemon listens on the server end, so flip around all your inbound/outbounds, and you have success. That is, on the server, open inbound port 1234, and outbound port 27000.

  • I just double checked my server settings and I see have both port exceptions as two-way (27000 for lmgrd.exe a.k.a. License Manager, and 1234 for clients a.k.a. ArcGIS Administrator). I'll leave the answer and graphic as is for the moment as I don't have time to verify what happens if the exceptions are tightened to specify in/outbound rules. I did re-examine the tech support case and it's correspondence to verify what is posted here matches the conclusion there, which it does. Feb 2, 2012 at 22:21

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