pfctl command HowTo - Linux / Unix Q & A from nixCraft

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

last updated January 14, 2018 in FreeBSD, OpenBSD, PF Firewall, Security

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?

OpenBSD / FreeBSD / NetBSD: PF Firewall List Rules

last updated December 6, 2012 in FreeBSD, OpenBSD, PF Firewall

I can use iptables -L -n command with Linux operating system to list the current firewall rules. How do I list all the current firewall rules under OpenBSD / FreeBSD / NetBSD operating systems? How can I see all pf firewall rules using command line tool?

MySQL/MariaDB Server: Bind To Multiple IP Address

last updated March 10, 2017 in Debian / Ubuntu, FreeBSD, Iptables, Linux, MySQL, PF Firewall, UNIX

I have MySQL database system running on FreeBSD. The server has multiple ip address. The mysqld used by many websites hosted on two other CentOS based servers. I would like to bind MySQL sever running on Unix / Linux server to more than one IP address such as 202.54.1.2, 202.54.1.10, and 202.54.1.15. How can I bind mysqld to multiple ips?

BSD PF Firewall Block FTP Bruteforce Attacks

last updated August 13, 2009 in Anti Spam, FreeBSD, Networking, OpenBSD, PF Firewall, Security, UNIX

I see lots of failed FTP login attempts in my log file. How do I stop FTP bruteforce attack? What should I do to solve this problem under FreeBSD 7.x server operating systems?

BSD FTP-Proxy: PF Firewall Allow Outgoing Active / Passive FTP Connections

last updated November 9, 2009 in FreeBSD, Networking, OpenBSD, PF Firewall, Security

Q. I’ve FreeBSD based Apache webserver. I need to allow outgoing ftp client requests so that BSD ports collection can download from various ftp sites. How do I allow outgoing FTP connection via PF network firewall software under FreeBSD or OpenBSD operating system?

FreeBSD / OpenBSD: PF Firewall Filter Large Number Of Subnets and IP Address

last updated August 31, 2008 in FreeBSD, Networking, OpenBSD, PF Firewall, Security

Q. How do I filter larger number of subnets and IPs using OpenBSD’s pf firewall under FreeBSD 7.x server? How do I log all dropped packets from such ips? How do I block upto 10000 IPs or subnet without any performance penalty?

axfr-get: fatal: unable to parse AXFR results: protocol error and Solution

last updated July 5, 2009 in Bind dns, Debian / Ubuntu, DJBDNS, Fedora Linux, FreeBSD, Iptables, Linux, Networking, OpenBSD, PF Firewall, Security, Troubleshooting, UNIX

I‘m trying to get data (AXFR query) from master tinydns server to secondary DNS server using tcpclient as follows:
tcpclient -v a.ns.example.com 53 axfr-get example.com example.com example.com.tmp

But I’m getting an error which read as follows:

>axfr-get: fatal: unable to parse AXFR results: protocol error

How do I fix this problem?