Iptables

Explains how to monitor bandwidth with Linux iptables command.

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Recently I came across very powerful and nifty tool called cutter. Just imagine that people in your private network using peer to peer (P2P) software such as Kazaa, iMesh or others and you want to cut them or just want to cut all ftp connection over your firewall but not all traffic to host. Network […]

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I already wrote about Linux command line bittorrent client. However, I received few more queries regarding firewall issues. Basically you need to open ports using iptables. Bittorrent client by default uses tcp 6881 to 6889 ports only. In order to work with Bittorrent client you need to open these ports on firewall. Remember, if you […]

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PostgreSQL is an object relational database system that has the features of traditional commercial database systems with enhancements to be found in next-generation DBMS systems. PostgreSQL is free and the complete source code is available. Open port 5432 By default PostgreSQLt listen on TCP port 5432. Use the following iptables rules allows incoming client request […]

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SMTP is used to send mail. Sendmail, Qmail, Postfix, Exim etc all are used on Linux as mail server. Mail server uses the TCP port 25. Following two iptable rule allows incoming SMTP request on port 25 for server IP address 202.54.1.20 (open port 25): iptables -A INPUT -p tcp -s 0/0 –sport 1024:65535 -d […]

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Sometime it is necessary to block incoming connection or traffic from specific remote host. iptables is administration tool for IPv4 packet filtering and NAT under Linux kernel. Following tip will help you to block attacker or spammers IP address. How do I block specific incoming ip address? Following iptable rule will drop incoming connection from […]

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Here is small script that does this. Debian or Ubuntu GNU/Linux does not comes with any SYS V init script (located in /etc/init.d directory) . You create a script as follows and use it to stop or flush the iptables rules. Please don’t type rules at command prompt. Use the script to speed up work. […]

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