Network security

General concepts

• Internet design goals and priorities
  • Packet switching
  • End-to-end principle
• Protocol layers
• Protocol encapsulation
• Data link, network, transport, application layers
• Broadcast

Link layer

• CAM overflow

• Switch table

• Forwarding & filtering

• Port security

• 802.1x

• Managed switch

• LAN vs. VLAN

• VLAN trunking

• 802.1Q, Extended Ethernet frame

• VLAN hopping attack

• Auto-trunking

Link layer - Network layer interaction

• ARP cache poisoning
• MAC address vs. IP address
• ARP table (cache)
• Gratuitious ARP
• Dynamic ARP inspection

Link-Network layer

• DHCP spoofing

Transport layer

• UDP packet forging
• TCP sequence numbers
• TCP sequence number prediction attack
• TCP SYN flooding attack
• SYN cookies

Network Layer - Routing

• Purpose of BGP
• BGP advertisements
• BGP hijacking
• Prefixes
• RPKI framework
• Longer route prefixes = More specific routes

DNS

• Domain Name System (DNS), DNS Resolver
• Pharming attack
• DNS spoofing attack (cache poisoning)
• DNS pharming attack
• Query ID
• DNSSEC
• DNS TTL (time to live)
• DNS Rebinding attack
• DNS pinning