nanog mailing list archives

Re: Strange 192.168. UDP/138 Traffic


From: Richard Welty <rwelty () averillpark net>
Date: Thu, 29 Jan 2004 13:51:39 -0500 (EST)


On Thu, 29 Jan 2004 12:24:15 -0600 Darrell Kristof <darrell.kristof () wholefoods com> wrote:


Hi everyone:

I'm having some strange traffic show up on my PIX.  Looking at the "show
conn" I have many many machines attempting to make outbound UDP/138
connections to 192.168.x.x addresses.  We don't have any 192.168.x.x
addresses inside the company.  This is blocked at our Internet router, so
it's not going out, but still would like to know what this is.

138 is NETBIOS (an MS protocol). look for windows clients that have
somehow gotten it in their head that they need to make a NETBIOS
connection to the cited RFC1918 space.

could this be a side effect of one of the current generation of viruses?

richard
-- 
Richard Welty                                         rwelty () averillpark net
Averill Park Networking                                         518-573-7592
    Java, PHP, PostgreSQL, Unix, Linux, IP Network Engineering, Security


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