What Is Norton IS 2011 Using Port 137 For?

I tightened up my NetBIOS firewall rules to only allow Local subnet. Low and behold I see in my logs that IS 2011 is attempting connect outbound UDP port 137 to the following domains and IPs:

 

shasta-rrs.symantec.com                    143.127.102.25

ipsg.crsi.symantec.com                        216.10.195.168

liveupdate.symantecliveupdate.com  207.86.164.49

 

What is this all about?

 

 

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