icmp problem

[Brad Knowles]

At 3:05 PM -0500 3/14/01, Joseph S D Yao wrote:

>>  Even if a spammer isn't doing this today, why leave it open to attack?
>
>  So your solution is to have the service not work per the RFCs.  Well,
>  that is one solution.  Another is to use the built-in network
>  protections to restrict access.  Or have firewalls or screening routers
>  or other such devices.

	Alternatively, he could turn off unused services like chargen. 
Any service that isn't running, is one that can't be compromised or 
used as part of a DoS attack.  Of course, this is not a security 
mechanism that should be used in a vacuum -- you still need the 
proper router filters, firewalls, etc....

--
Brad Knowles, <brad.knowles at skynet.be>

#!/usr/bin/perl -w
# 531-byte qrpff-fast, Keith Winstein and Marc Horowitz <sipb-iap-dvd at mit.edu>
# MPEG 2 PS VOB file on stdin -> descrambled output on stdout
# arguments: title key bytes in least to most-significant order
# Usage:
# qrpff 153 2 8 105 225 /mnt/dvd/VOB_FILE_NAME | extract_mpeg2 | mpeg2_dec -
$_='while(read+STDIN,$_,2048){$a=29;$b=73;$c=142;$t=255;@t=map{$_%16or$t^=$c^=(
$m=(11,10,116,100,11,122,20,100)[$_/16%8])&110;$t^=(72, at z=(64,72,$a^=12*($_%16
-2?0:$m&17)),$b^=$_%64?12:0, at z)[$_%8]}(16..271);if((@a=unx"C*",$_)[20]&48){$h
=5;$_=unxb24,join"", at b=map{xB8,unxb8,chr($_^$a[--$h+84])}@ARGV;s/...$/1$&/;$
d=unxV,xb25,$_;$e=256|(ord$b[4])<<9|ord$b[3];$d=$d>>8^($f=$t&($d>>12^$d>>4^
$d^$d/8))<<17,$e=$e>>8^($t&($g=($q=$e>>14&7^$e)^$q*8^$q<<6))<<9,$_=$t[$_]^
(($h>>=8)+=$f+(~$g&$t))for at a[128..$#a]}print+x"C*", at a}';s/x/pack+/g;eval