OpenBSD – nixCraft

How to find disk I/O latency with ioping monitoring tool on Linux

September 21, 2017in FreeBSD, Linux, Mac OS X, OpenBSD, UNIX last updated September 21, 2017

How do I monitor disk I/O latency in real time on Linux, FreeBSD, OpenBSD, and MacOS operating system?

How To Set Up a Firewall with PF on FreeBSD to Protect a Web Server

August 29, 2017August 29, 2017in FreeBSD, OpenBSD, PF Firewall, Security last updated August 29, 2017

I am a new FreeBSD server user and moved from netfilter on Linux. How do I setup a firewall with PF on FreeBSD server to protect a web server with single public IP address and interface?

How to change or configure OpenBSD package install mirror

August 16, 2017in OpenBSD, Package Management, UNIX last updated August 16, 2017

openbsd commandI am trying to install nginx server on OpenBSD but keep getting an error that read as follows when I run the pkg_add command:

https://mirror.leaseweb.com/pub/OpenBSD/6.1/packages/amd64/quirks-2.304.tgz” title=”quirks-2.304.tgz: ftp: Error retrieving file: 404 Not Found
signify: gzheader truncated
https://mirror.leaseweb.com/pub/OpenBSD/6.1/packages/amd64/nginx-1.10.2p2.tgz” title=”nginx-1.10.2p2.tgz: ftp: Error retrieving file: 404 Not Found
signify: gzheader truncated

How do I change or configure OpenBSD package install mirror for the pkg_add command?

How to allow root login from one IP address with ssh public keys only

June 10, 2017in CentOS, Debian / Ubuntu, FreeBSD, Linux, OpenBSD, RedHat and Friends, Suse, UNIX last updated June 10, 2017

I am using MacOS on the desktop and Ubuntu Linux on the server. I disabled root login over ssh and enabled ssh based public key login. However, I recently added second Ubuntu server. I need to sync file between two using rsync command. Is there any way that I can log from the second server into my first server with root user from second server IP address only ({root@secondBOX }# ssh root@firstBOX1) without reducing OpenSSH server security option?

How to disable ssh password login on Linux to increase security

February 17, 2017February 17, 2017in CentOS, Debian / Ubuntu, Linux, OpenBSD, RedHat and Friends, Security, Suse last updated February 17, 2017

I want to disable ssh clients from accessing using the password and only allow ssh login using SSH keys. How do I disable password authentication for SSH on Linux operating systems?

How to install denyhosts on Ubuntu Linux 16.04 LTS ( intrusion prevention security tool )

February 12, 2017February 12, 2017in Debian / Ubuntu, Linux, OpenBSD, Security, Ubuntu Linux last updated February 12, 2017

I host my blog in cloud server, and I set up ssh to manage my Ubuntu Linux 16.04 LTS server. However, I noticed lots of break in and brute-force attacks on my ssh server? How can I stop hacking attempts into my system?

Linux/Unix: Force ssh client to use only password auth authentication when pubkey auth configured

January 21, 2017January 21, 2017in CentOS, Debian / Ubuntu, FreeBSD, Linux, OpenBSD, RedHat and Friends, Suse, UNIX last updated January 21, 2017

I configured and use my openssh server to accept only public key based authentication. I need to test if my server accepting password. How to allow ssh client to use only password auth when pubkey auth configured?