Challenges - The Iptables Command: Lab 1

linux-security-the-complete-iptables-firewall-guide-lab-1.md

iptables challenges 101

1. Write the iptables commands that set the default POLICY to ACCEPT on INPUT and OUTPUT chains and DROP on FORWARD chain.

iptables -P INPUT ACCEPT
iptables -P OUTPUT ACCEPT
iptables -P FORWARD DROP

2. Write the iptables command that lists only the filter table of INPUT chain.

iptables -t filter -vnL

3. Write the iptables commands that list the nat table.

iptables -t nat -vnL

4. Write the iptables command that flushes the filter table of all chains.

iptables -t filter -F

5. Write an iptables rule that drops all incoming packets to port 22/tcp (ssh). This should be the first rule in the chain.

iptables -t filter -I INPUT -p tcp -dport 22 -j DROP

6. Write the iptables commands that flush all the tables of all chains and set the ACCEPT policy on all chains. This will delete any firewall.

iptables -t filter -F
iptables -t nat -F
iptables -t mangle -F
iptables -t raw -F

iptables -P INPUT ACCEPT
iptables -P OUTPUT ACCEPT
iptables -P FORWARD ACCEPT