Authormr51m0n – a network numbers search engine

Today I’d like to introduce to you:, my latest project.

It’s a little web app where you can search for an IP, an Autonomous System number or a domain name to find information about those.

Although I’m perfectly aware of the fact that there are already numerous tools out there that have similar functionality, I started with developing  It began mainly a an exercise in Golang, internet technologies in general and, most importantly, for fun.

But the topic was not randomly chosen: I always had to copy & paste information for an IP from different sources until I had all the information I needed together when working at my day job.

So I also did it to have a tool at hand to which I can throw IPs, ASN Numbers, domain names, etc.. and it would always respond something

In this first public release I’m not quite there. MAC addresses, for example, are not yet supported (but will be once), Whois information is not yet as complete as I’d like it to be (getting correct Whois information is not as easy as I thought, but that’s enough material for another post.) and It’s not yet possible to search for companies and get their assigned AS Numbers back. (but it’s planned as well.)

Also I plan to provide an API for all the information you can now see in the results of a query for easy access in your apps.

Nevertheless I’m happy with the result so far and I’ll keep improving the site continuously.

If you have the time and like using, I’d be very happy to hear from you and receive feedback. Maybe you have an idea that could make more useful for you? Maybe something about it totally sucks and I better change it? Let me know: is on twitter, has a simple contact form for feedback or you may simply leave a comment below.

Hope to see you on,


The fastest rsync over SSH options

When synchronizing a ton of data you don’t want to wait longer than really necessary! So I tested several suggestions found on the net and came up with the following:

rsync -aHxv --numeric-ids --delete --progress -e "ssh -T -c arcfour -o Compression=no -x" <source_dir> <user>@<dest>:<dest_dir>

This command is almost exactly what somaddict suggested on

Optimizing/Compressing PDF Files

To reduce the size of a PDF, you may try run this command on a linux box:

gs -sDEVICE=pdfwrite -dCompatibilityLevel=1.4 -dPDFSETTINGS=/ebook -dNOPAUSE -dQUIET -dBATCH -sOutputFile=output.pdf input.pdf

If the -dPDFSETTINGS=/ebook option produces too pixeled pictures, try -dPDFSETTINGS=/prepress, if you need an even smaller file size, try -dPDFSETTINGS=/screen.

Only Threema rated uncritical, Telegram rated critical for privacy

The German “Stiftung Warentest” had a closer look (text is german) at instant messengers like WhatsApp, Telegram and Threema. The only one with a good privacy rating: Threema.

When Facebook bought WhatsApp, many started to look for alternatives. Telegram was chosen by millions of new users, probably also because it’s free to use. The problem with things free to use on the internet is this: If something’s free on the internet, you are the product.

This seems to be true yet again – Telegram uploads your full address book to the operators servers, of course without asking for your permission first. This is even more critical when one of the creators of Telegram is VK, the Russian Facebook alternative.

Contrary to that, the swiss based Threema asks for your permission to upload your address book and it’s used for synchronization purposes only. Even if uploaded, only aliases are transmitted.

Only Teleram and Threema provide useful end-to-end encryption, but on Telegram it has to be enabled explicitly (Secret Chat), while on Threema you can’t even disable it.

One constraint is left: none of the tested app is open source.

nginx server status page and interpretation

Server tuning starts with server monitoring, with server-stats you can learn about the usage of nginx.

First, check if nginx has been compiled with –with-http_stub_status_module.

$ /usr/sbin/nginx -V 2>&1 | grep --color with-http_stub_status_module

Check the output for –with-http_stub_status_module. If it’s not there, you must compile it in manually.

If you have it, start by add this config snippet to your server config:

server {
  location /server-status {
    stub_status on;
    access_log off;
    deny all;

Then, reload nginx. You can query the status page from localhost only with this config. Try it:

$ wget -qO -

Active connections: 4
server accepts handled requests
488803 488803 1002230
Reading: 0 Writing: 2 Waiting: 2

This reads like this:

We have 4 active connections, 2 of them are currently being served by nginx (Writing), 0 are requesting something (Reading) and 2 have open connections but there is no activity at the moment (Waiting), this is because of keep-alive connections.

The server has accepted 488803 connections and could answer 488803 of it (100%). Within this connections, 1002230 requests have been served (2.05 requests/connection).

© 2017 netmess

Theme by Anders NorenUp ↑