nanog mailing list archives

Re: Customer-facing ACLs


From: Dave Pooser <dave.nanog () alfordmedia com>
Date: Sat, 08 Mar 2008 00:59:17 -0600


Port 22 outbound? And 23?  Telnet and SSH _outbound_ cause that much of a
concern? I can only assume it's to stop clients exploited boxen being used
to anonymise further telnet/ssh attempts - but have to admit this
discussion is the first i've heard of it being done 'en masse'.

On one test machine that I leave SSH unfirewalled on, I'll see 200-4000 SSH
login attempts per day, trying to brute force it. Lets see, this morning in
an eight-minute span from one IP in Aruba 100 attempts for root; other
usernames attempted include admin, staff, sales, office, alias, stud (!),
trash, guest, test, oracle, a few personal names, apache, svn, iraf, swsoft,
gast, sirsi and nagios. And this is a relatively slow day.

Telnet I wouldn't know about, but I'm told bots will try to force it as
well.
-- 
Dave Pooser, ACSA
Manager of Information Services
Alford Media http://www.alfordmedia.com




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