Re: "System" Wants to Connect Out on Ports 137, 138, 139 (udp)

From: Don Kelloway (dkelloway_at_commodon.com)
Date: 08/31/04

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    Date: Tue, 31 Aug 2004 04:04:23 GMT

    "Treeslug" <tree@slug.com> wrote in message
    news:jsk6j0995djmega4b3g89jf2elh2ltonvt@4ax.com...
    > WindowsXP Home
    >
    > According to Kerio 2.1.5 the computer (System) keeps trying to connect
    > out with ports 137-139.
    >
    > What is this, and should I block it?

    UDP ports 137, 138 and TCP 139 are used by Microsoft's NetBIOS protocol
    which is commonly used by Windows computers to map/share drives, transfer
    files, etc.

    If your PC is considered home use only there is no legitimate reason to
    allow this traffic outbound past your firewall. Additional ports to ensure
    that you don't allow outbound include ports 135 and 445. 

    -- 
Best regards, from Don Kelloway of Commodon Communications
Visit http://www.commodon.com to learn about the "Threats to Your Security 
on the Internet".
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