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various raspbian x posts



On Monday 30 December 2019 03:48:54 Andrei POPESCU wrote:

> On Du, 29 dec 19, 18:57:12, Gene Heskett wrote:
[...]
>
> Could you please provide some examples?

This one has to do with building a pre-empt-rt kernel for armhf, which 
allows linuxcnc to run in uspace. But subjectwise it wanders badly but 
I'd like to show one full chain of recent events: 

Raspbian claims to have such a src tree if you want to build it yourself.
But it was not updated for 10.1 when the default was updated, so we were 
stuck with video running at about 1.5 fps.  I know, I built it.  So I 
asked for clarification and got a "thats how it is answer" from 
raspbian.  I knew better than come here, so I was on my own.  So since 
I'm lurking on the linux-rt list, I went back in time to a 4.19 kernel 
src tree and built it, quite successfully I think, getting around 57 fps 
out of glxgears pulled out to full screen. But linux-rt is not a usr 
list and usr's asking build questions there are generally ignored.

You can dl that kernel from my web site, along with the debs to install 
linuxcnc on your rpi4, and 2 or 3 others have done so. My web site shows 
my rather eclectic interests, and hadn't generated a huge amount of 
traffic from the bots as they were simply indexing it and moving on, 
using perhaps 10Gb a month.

But with my putting that up, every bot on the planet suddenly started 
mirroring it all, quite a few gigabytes, and fighting for bandwidth as 
they were doing it in a loop, when they got done, they restart it again. 
With my connection speed, that can be defined as a DDOS attack.

Never before have I felt the need to block them but when the bots started 
ignoring my robots.txt files and using 99% of my uploads bandwidth for 
weeks on a 24/7 basis I came here for help as the manpage for iptables 
may as well have been written in swahili. Eventually I got the help, 
made bash scripts out of 3 cli examples that were posted, and did get 
most of them that ignored the robots.txt stopped.

Many of the replies I got weren't terribly usefull, suggesting I install 
a whole kit of automatic stuff that needed its own programming setup to 
become effective, and most of the suggested stuff, like fail2ban 
depending on a failure to trigger their actions, but that meant you had 
to have failures, but the bots were very successfull so there weren't 
any failures. But that little detail wasn't understood by the responders 
here.  So I had to keep hammering on it.  That doesn't exactly endear to 
the list either.

I try to ask pertinent questions here, as I have 4 machines here running 
stretch right now, with the rpi4 running raspbian buster, but as an 
example, thats not a good one for the quality of the help I got for 
asking how to put iptables to work. I now have an iptables status report 
with about 35 xx.xx.xx.xx/24 drops and its working. But it took many 
posts to accomplish what I thought was a very specific task.

And I'm back to fetchmail using the majority of my used bandwidth, so I'm 
a happy camper again.

Thank you Andrei POPESCU (and others) for reading my tale of woe.

Cheers, Gene Heskett
-- 
"There are four boxes to be used in defense of liberty:
 soap, ballot, jury, and ammo. Please use in that order."
-Ed Howdershelt (Author)
If we desire respect for the law, we must first make the law respectable.
 - Louis D. Brandeis
Genes Web page <http://geneslinuxbox.net:6309/gene>


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