Subject: Re: heads up, ftp attacks
To: Andrew Gillham <gillhaa@ghost.whirlpool.com>
From: Wolfgang Rupprecht <wolfgang@wsrcc.com>
List: current-users
Date: 02/26/1998 10:49:25
Andrew Gillham writes:
> Yeah, the "Warez boyz" got you..
Yep, certainly did. I did get a nice list of 3500 ip addresses out of
the deal though. They are just the thing for feeding to my blackhole
filter.
> FWIW, why do you think your NetBSD box crashed? Shouldn't the TCP
> state engine handle the problem? Or was it just the fact that so many
> ftp processes were forked you ran out of swap?
These are very good questions. I was wondering that myself. I doubt
that netbsd boxes ever get tested under these sorts of loads. Short
of putting up a warez site, how does one get enough test machines to
ftp from. ;-)
I do have a touch on the large side of swap, but its not clear how
many ftp's were running before the crash.
$ pstat -s
Device 1K-blocks Used Avail Capacity Priority
/dev/sd0b 282150 4 282146 0% 0
/dev/sd1b 313500 4 313496 0% 0
Total 595650 8 595642 0%
There are a few things that could take some looking into. After I
rebooted the first time I did see the following pop up after a minute
or two:
Data modified on freelist: word 6 of object 0xf0b19880 size 128
previous type temp (0xf0b52800 != 0xdeadbeef)
Data modified on freelist: word 6 of object 0xf0b19880 size 128
previous type temp (0xf0b52800 != 0xdeadbeef)
I had different fires to fight at the time, so I just ignored it.
-wolfgang
--
Wolfgang Rupprecht <wolfgang@wsrcc.com> http://www.wsrcc.com/wolfgang/
Never trust a program you don't have sources for.