RE: Turn off PING server on AS/400

Not to mention, if your firm has a Class C or, better, a Class B or
more, blocking ICMP at the firewall doesn't give away which of the
addresses in your address range have servers; you still have to
determine that via port scan or other means.

John A. Jones
Americas Security Officer
Jones Lang LaSalle, Inc.
V: +1-630-455-2787 F: +1-312-601-1782
John.Jones@xxxxxxxxxxxxxxxxxxxxxxx

-----Original Message-----
From: Adam Lang [mailto:aalang@xxxxxxxxxxxxxxxxxxxx] 
Sent: Thursday, May 13, 2004 8:48 AM
To: Midrange Systems Technical Discussion
Subject: Re: Turn off PING server on AS/400

Well, the DOS attack only works (unless there is a bug in your
computer's TCP/IP stack) if the pinger can generate more traffic than
your system has bandwidth available.

Now, if theoretically I ever tried to crack a system, I wouldn't care
about ping.  You run a port scan against the IP address.  You can't
block ports that you have to legitimately have open.  So, blocking ICMP
only stops the lazy or stupid cracker.
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