[Lula] Harrassing spammers WAS Re: Mail server ip changed issue.

[Jeff Carlson]

Peter Benjamin wrote:
> Oh, not the packet, but number of packets changes from 1 packet of
> size 1506, to 1506 packets with a data payload size of 1, if I
> correctly understood your description of spamd.

Yeah, now think about those 1500 packets being sent at one per second. 
Now what used to take a single packet, near instantaneous transfer at 
the speed of light, now takes about 25 minutes.  That is not high 
bandwidth on my server, but it is 25 minutes a spammer has wasted in a 
single-threaded delivery mode.  And think about it, most spammers are 
using a hijacked PC anyway, how are they going to know their 
single-threaded virus wasted half an hour delivering one message, and 
failed on top of that!?  If the spam software actually queues and tries 
again, it will fail again.

>> I could look it up but laziness prevails.  And for another thing, I
>> don't get a steady, unending stream of email to my home server.
> 
> Oh, not yet.

When that day comes, I'll need to start blocking a lot more sources.

> Oh, yes, using the TCP layer for ACKing the reception of the 41 byte 
> packet, could be limited.  But that does not mean the sending 
> computer, or rather the router that needs to repacket from the MTU of
> 1506 down to a packet size of 1, is going to wait for the ACK...

TCP is layer 4.  I think what we're actually doing is changing the MTU, 
which is layer 1.

A better word for "repacket" is "fragment."

> And whose router is likely going to get hammered?  Your ISP's?

No, because the router will refuse to queue too much, and it will slide 
the MTU downstream down to smaller and smaller values until the sending 
machine is matching the MTU I set.

> Or is the thought that spamd's request for a data size of 1 byte, is
> going to go all the back to the mail client computer or it's upstream
> router, where the data size will change?

Yeah.  Routers don't have infinite memory.  You know, Mark Nagle would 
be the right guy to really ask about this.  You're right, this is the 
wrong list for this.  :)

_______________________________________________
Lula mailing list
Lula at lula.org
http://www.lula.org/mailman/listinfo/lula