Defense in AaD

Basic of Computer Network

• Network
• Nodes
• Protocol
• Topology
• Service Provider Network
• IP Address
• DNS
• Firewall

Basic terminologies:

Network devices

OSI Model:

Packet:

ASCIS Architecture

Faust CTF Architecture

RuCTF Architecture

IPTables

Tables:

INPUT CHAIN

OUTPUT CHAIN

FORWARD CHAIN

FILTER TABLE

OUTPUT CHAIN

PREROUTING CHAIN

POSTROUTING CHAIN

NAT TABLE

INPUT CHAIN

OUTPUT CHAIN

FORWARD CHAIN

MANGLE TABLE

PREROUTING CHAIN

PREROUTING CHAIN

IPTables Flow

Command

• iptables-save > /tmp/dump.txt
• iptables -F
• iptables-restore < /tmp/dump.txt
• iptables -nvL -t filter
• iptables -A FORWARD -p tcp –dport 80 -j ACCEPT
• iptables -I FORWARD 1 -t filter -p tcp \

-d [vulnbox_ip] –dport [service_port] \

-m string –string “[payload]” –algo bm \

[-m string –hex-string “| [hex] |” –algo kmp \]

-j DROP

Demo IPTables

IPTables Alternative

END