Stopping ip range scans
John R. Levine
johnl at iecc.com
Mon Dec 29 17:42:32 UTC 2003
My router is set up to send me daily reports of IP addresses that hit
the port 137-139 block more than 1000 times a day. The sources are
all over the place, including a lot of IANA reserved address space
that Sprint and my ISP should be filtering upstream, but a lot of the
scans are from hosts on my ISP's network that I know are consumer DSL.
My working assumption is that these are worms looking for new hosts to
attack. When I have time, I tell the ISP about the local ones so they
can tell their customer to fix it, otherwise I don't bother.
So long as you have reasonable router filters, port scans are an
annoyance but not a security issue.
John R. Levine, IECC, POB 727, Trumansburg NY 14886 +1 607 330 5711
johnl at iecc.com, Village Trustee and Sewer Commissioner, http://iecc.com/johnl,
Member, Provisional board, Coalition Against Unsolicited Commercial E-mail
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