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firewall rules

OpenBSD / FreeBSD / NetBSD: PF Firewall List Rules

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?
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RHEL / Centos Linux Disable Firewall

How do I disable firewall on CentOS or Red Hat Enterprise Linux server version 5.x/6.x running on my HP micro server?
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HowTo: Unix / Linux Remove (Delete) OpenSSH Server

I'm new to Linux and my boss told me to remove ssh server as we don't need to provide the remote login and file transfer capabilities of SSH. How do I disable and remove OpenSSH server?
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Linux Deleting Firewall Rules

I would like to to delete my iptables based firewall rules under Linux. How do I delete rules individually or all at once under CentOS or Fedora Linux or RHEL based servers?
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Disable / Turn Off Firewall in Ubuntu Linux Server

How do I disable the firewall in Ubuntu Linux server edition? How do I turn off the firewall in Ubuntu Linux version 12.04 or 14.04 LTS server?
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Linux Iptables Open LDAP Server TCP Ports 389 and 636

The default Iptables configuration under CentOS / Red Hat / RHEL / Fedora Linux does not allow inbound access to LDAP service. How do I update iptables settings to allow access to the LDAP primary TCP #389 and encrypted-only TCP # 636 ports, while keeping all other ports on the server in their default protected state?
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Understanding CentOS Default -A RH-Firewall-1-INPUT -p 50 -j ACCEPT Firewall Rule

Q.Can you explain the meaning of following two firewall rules present in my /etc/sysconfig/iptables rules under CentOS Enterprise Linux version 5.2?

-A RH-Firewall-1-INPUT -p 50 -j ACCEPT
-A RH-Firewall-1-INPUT -p 51 -j ACCEPT
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axfr-get: fatal: unable to parse AXFR results: protocol error and Solution

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?
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How to: Allow telnet and ssh through iptables under Linux

Q. I run both RHEL / CentOS Linux server and by default firewall blocked out everything including telnet / ssh access. How do I allow telnet - port 23 and ssh port 22 thought Linux iptables firewall ?

A.By default firewall rules stored at /etc/sysconfig/iptables location / file under CentOS / RHEL. All you have to do is modify this file to add rules to open port 22 or 23.

Login as the root user.

Open /etc/sysconfig/iptables file, enter:
# vi /etc/sysconfig/iptables
Find line that read as follows:
To open port 22 (ssh), enter (before COMMIT line):

-A RH-Firewall-1-INPUT -m state --state NEW -m tcp -p tcp --dport 22 -j ACCEPT

To open port 23 (telnet), enter (before COMMIT line):

-A RH-Firewall-1-INPUT -m state --state NEW -m tcp -p tcp --dport 23 -j ACCEPT

Save and close the file. Restart the firewall:
# /etc/init.d/iptables restart

HowTo Disable The Iptables Firewall in Linux

I need to disable firewall in Linux for testing purpose. I'm using CentOS and RHEL version 4.4 / 5 / 6. How do I disable the firewall in Linux?
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