第2次作业

安全课程作业

Network Security and Attacks

第3部分 Firewalls

题目答案

++++++++++++++++++++++++
Alice.rules
++++++++++++++++++++++++

iptables -A INPUT -i lo -j ACCEPT
iptables -A OUTPUT -o lo -j ACCEPT
iptables -A INPUT -p tcp --dport 22 -j ACCEPT 
iptables -A INPUT -p tcp --dport 80 -j ACCEPT
iptables -A INPUT -p tcp --dport 443 -j ACCEPT
iptables -A INPUT -p tcp --dport 21 -j ACCEPT  
iptables -A INPUT -p tcp --dport 21 -j ACCEPT 
iptables -A INPUT -p udp --dport 4445 -j ACCEPT 
iptables -A INPUT -j DROP
iptableS -A OUTPUT -p tcp --dport 20 -j ACCEPT
iptableS -A OUTPUT -p tcp --dport 21 -j ACCEPT
iptables -A OUTPUT -j DROP

+++++++++++++++++++++++++
Bob.rules
+++++++++++++++++++++++++

iptables -A INPUT -i lo -j ACCEPT
iptables -A OUTPUT -o lo -j ACCEPT
iptables -A INPUT -p tcp --dport 22 -j ACCEPT
iptables -A INPUT -p tcp --dport 8080 -j ACCEPT 
iptables -A INPUT -p udp --dport 4444 -j ACCEPT 
iptableS -A OUTPUT -p tcp --dport 20 -j ACCEPT
iptableS -A OUTPUT -p tcp --dport 21 -j ACCEPT
iptables -A OUTPUT -j DROP
iptables -A INPUT -j DROP

++++++++++++++++++++++++++
Charlie.rules:
++++++++++++++++++++++++++

iptables -A INPUT -i lo -j ACCEPT
iptables -A OUTPUT -o lo -j ACCEPT
iptables -A INPUT -p tcp --dport 22 -j ACCEPT
iptables -A OUTPUT -j DROP
iptables -A INPUT -j DROP

题目收获

• iptables 默认防火墙策略参考

iptables -A INPUT -i lo -j ACCEPT
iptables -A OUTPUT -o lo -j ACCEPT
iptables -A INPUT -p tcp --dport 22 -j ACCEPT
iptables -A OUTPUT -j DROP
iptables -A INPUT -j DROP