IT Security Stuff

Monitor and block SSH connection attempts. Here is a simple guide for iptables... This will set iptables to default: ........ sudo iptables -P INPUT ACCEPT sudo iptables -P OUTPUT ACCEPT sudo iptables -P FORWARD ACCEPT Then flush the rules: sudo iptables -F INPUT sudo iptables -F OUTPUT sudo iptables -F FORWARD This allows you to view your current rules: $ sudo iptables -L ........ Install iptables-persistent package to save tables on reboot. $ sudo apt-get install iptables-persistent During the installation, you will asked if you want to save your current firewall rules. If you update your firewall rules and want to save the changes, run this command: $ sudo netfilter-persistent save $ sudo netfilter-persistent reload ........ With the following, an attacker is allowed to produce exactly 3 faulty logins in 2 minutes. Afterwards, they will be blocked for 120 seconds. 1) Add the following line to /etc/ssh/sshd...

 Ip tables is a command line firewall that comes with linux. Its essential to learn how to use the different parts of it for the scanning phase: IPTABLES: iptables has the following 4 built in tables:   i.FILTER table: it has 3 chains:           1.INPUT chain- incoming to the firewall           2.OUTPUT chain- outgoing from the firewall           3.FORWARD chain-packets for another NIC on the local server   ii.NAT table: it has 3 chains:           1.PREROUTING- alters packets before routing. (used for DNAT , destination nat)           2.POSTROUTING – alters packets after routing. (used for SNAT , source nat)           3.OUTPUT – used for packets generated locally    iii.MANGLE table: specialized packet alteration. It m...