Increase your Linux server Internet speed with TCP BBR congestion control

in Categories Cloud Computing last updated July 22, 2017

I recently read that TCP BBR has significantly increased throughput and reduced latency for connections on Google’s internal backbone networks and google.com and YouTube Web servers throughput by 4 percent on average globally – and by more than 14 percent in some countries. The TCP BBR patch needs to be applied to the Linux kernel. The first public release of BBR was here, in September 2016. The patch is available to any one to download and install. Another option is using Google Cloud Platform (GCP). GCP by default turned on to use a cutting-edge new congestion control algorithm named TCP BBR.

Why port 80 (HTTP) reported as open by nmap when it is closed?

in Categories Security last updated July 2, 2017

Why are some ports reported as open by nmap?
I recently setup a small server which is running Debian 9. The purpose of this machine is to run OpenVPN server on port 443 to bypass censorship. It runs the following services and nothing else:

  1. Squid on private IP belongs to VPN pool (10.8.0.1:3128)
  2. SSH on private IP belongs to VPN pool (10.8.0.1:22)
  3. DNS resolver on private IP belongs to VPN pool (10.8.0.1:53)
  4. OpneVPN on public IP port 443 (server_public_ip_address:443)

Download of The Day: Debian Linux 9 ( Stretch )

in Categories Linux News last updated December 1, 2017

Debian GNU/Linux version 9.0 stretch has been released ( jump to download ) after many months of constant development and available for download in various media format. Debian 9.0 is a free operating system includes various new features such as support for mips64el architecture, GNOME 3.22, KDE Plasma 5.8, LXDE, LXQt 0.11, MATE 1.16, Xfce 4.12, Linux kernel 4.9 and more. Debian 9 is dedicated to the project’s founder Ian Murdock, who passed away on 28 December 2015.
Debian 8.x 64-bit-mate-desktop-screenshot

Is my Linux server or desktop affected by WannaCrypt ransomware?

in Categories Security last updated May 18, 2017

From my mailbag:

Dear nixCraft,

I run a Debian Linux 8.x on my Desktop and Ubuntu Linux 16.04 LTS on my Linode cloud server for my personal website. I am concerned that my Linux is affected by the recent Wannacrypt malware. I am reading about a ransomware attack, what do I need to do? Should I be worried?

–Concerned Linux User

GnuBee: Personal blobfree NAS/Cloud server for hackers

in Categories Hardware last updated May 2, 2017

GnuBee is a personal NAS (Network Attached Storage) cloud server that is currently being funded on Crowd Supply. It is a low-cost, low-power, NAS device that runs GNU/Linux and it is claimed to be based on free, libre, and open source software. No proprietary drivers needed to use GnuBee.

Eyegasm: 5 awesome Linux/Unix desktop customization that will blow your mind

in Categories Hardware, Open Source last updated April 21, 2017

Everyone loves the desktop operating system. People customize their Linux or Unix desktop with themes, wallpapers, killer configuration and more. These customizations show you how cool your desktop can be!
awesome Linux/Unix desktop customization that will blow your mind

How to use parallel ssh (PSSH) for executing ssh in parallel on a number of Linux/Unix/BSD servers

in Categories Cloud Computing, Command Line Hacks, Howto last updated April 21, 2017

Recently I come across a nice little nifty tool called pssh to run a single command on multiple Linux / UNIX / BSD servers. You can easily increase your productivy with this SSH tool.

More about pssh

pssh is a command line tool for executing ssh in parallel on some hosts. It provides specialties includes:

  1. Sending input to all of the processes
  2. Inputting a password to ssh
  3. Saving output to files
  4. IT/sysadmin taks automation such as patching servers
  5. Timing out and more

Let us see how to install and use pssh on Linux and Unix-like system.

pssh-welcome

How to protects Linux and Unix machines from accidental shutdowns/reboots with molly-guard

in Categories Command Line Hacks, Debian Linux, Hardware last updated February 19, 2017

Oops! I did it again. I thought I was logged into my home server. Turns out I rebooted the db server. Another my not so favorite is typing “shutdown -h 0” into the wrong terminal. I know a few people who have admitted to doing that here.

My anger that can't be contained
Is there any end to the madness? Do I need to suffer from accidentally random reboots and shutdowns? After all, it is human nature to make mistakes, but one should not keep on making the same mistakes again and again.