Archive for June, 2015

Ethernet/IP/TCP bitrate vs. packet size vs. segment size vs. efficiency vs. speed

Friday, June 26th, 2015

The shiny title says network interface supports 100 Mbit/s. Ok, I should get 100/8=12.5MB/s or 11.9MiB/s out of it, right? Right? Well, not exactly. As it turns out, running stacked protocols has its penalty. Let us explore what lies beneath.

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Network speed testing discrepancy: iperf vs. iftop vs. iptraf

Thursday, June 25th, 2015

WARNING: This content is obsolete and inaccurate. Here is updated content, presented with a new approach.

 

When I need to test raw network performance, I usually rely on iperf. It is a simple and solid single-threaded network performance testing tool. But if I want a quick glance of what is going on on the network interface right now, I usually use iptraf. The third tool that is also simple and usually readiliy available is iftop.

But if you run a network bandwidth test with iperf and watch the network throughput with iptraf and/or iperf, you will notice the discrepancy in results.

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Frustration with Stack Exchange et al

Monday, June 15th, 2015

 

rantNow() {
return ”
This is the problem I have with users on Stack Exchange / Stack Overflow / Server Fault etc.

I like SO/SE/SF. A lot. Their website provides many answers, which are
correctly indexed by Google. This means they are easy to find. Cool.

I work with Linux systems, a lot. Searching the web for error messages that
occur during my work is part of the process. I am thankful that SO provides
many answers. So officially: THANK YOU!

Every once in a while I get to SO question that either:
a) does not have answer at all, or
b) the answer is given, but my case is a bit different, yet it results
with the same error, so the answer does not apply.

Usually I figure things out, eventually. If certain SO answer was a bit helpful,
I try to contribute back what, in my case, caused and what fixed the error. Cause,
you know, FOSS spirit, good samaritans, or a temporary goodwill that will perish with the next the-website-is-down phone call. Whichever.

Here is the rub:
EVERY FSCKING TIME I CONTRIBUTE, SOME RETARDED CONTENT POLICY NAZI BARKS SOME
IRRELEVANT SHIT BACK TO ME!

Here are the most common responses:

Nazi: “Your post does not provide answer to the question!”

Yes it does. Why do you think I am contributing to this question? Because it is
the first hit on Google when I searched for this error message. Does not answer
it 100%? Could be, but 6 hours ago a hint like the one I just contributed would
save me 6 hours of Googling and research – isn’t you website exactly about this?
STOP YOUR FUCKING REPUTATION-WHORING!

Nazi: “Your answer does not provide steps to fix the issue!”

Fuck you! Kindergarten is further down the road, there you will be provided with
step-by-step guide how to FUCK OFF.
Seriously, if the question is something that only a professional would look for,
do you REALLY think that said professional needs your baby-step-by-step guide???
No, she/he does not. What is needed is a hint in the right direction, everything
else is too environment-specific.
STOP YOUR FUCKING REPUTATION-WHORING!

Nazi: “You should include steps for installation here, not just URI to HOWTO!”

What do you think, 1 year down the road, which installation guide will still
be acurate? The one on SO that I (project maintainer) will forget about the very
second I post it, or the one on the official project page, where I maintain the
most up to date installation instructions, including backwards-compatibility for
as much versions as possible?
STOP YOUR FUCKING REPUTATION-WHORING!

Nazi: “You should put this as a comment to the question!”

First, FUCK YOU! If you have Xk reputation points, I do not. I do not want them,
I am not in a market to collect them, or to be whoring for them. But as I have
less than Y points, I am UNABLE TO POST COMMENTS TO QUESTIONS YOU FUCKING MORON.
Check my reputation first, and stop shitting on my head.

Again: STOP YOUR FUCKING REPUTATION-WHORING!

Normal SO user response: “Your wording/style is not OK. I fixed it for you.”

Eee, thanks, mr. first normal person in a long while. It has been so long since
I last received such a normal response, I really do not know what to say right
now. I hope you get reputation points for your edit.

To other REPUTATION WHORING MORONS:

Did I provide invalid answer? Fine, delete it. Or, even better, leave it
there, for me and others to learn, and provide a corrected version too.

I guess it is easier to get reputation points by criticising other comments
than actually providing genuine content. I guess you think you need your
reputation points for your next job, where you will be able to hide your
inability to produce genuine content. Or something similar. I understand
your logic, and if I was incapable of producing anything meaningful, this
would be my strategy too. But as I am not, this is my response to you:

YOU GO TO HELL! YOU GO TO HELL AND YOU DIE! And, oh yeah, another thing: FUCK YOU! WITH A FORK! UP YOUR BUTT!


}
rantNow > /dev/null