5. INTERNET LAYER - FORWARDING

• 5.1 INTRODUCTION
• 5.2 FORWARDING WALK-THROUGH
  • 5.2.1 Forwarding Algorithm
    • 5.2.1.1 General
    • 5.2.1.2 Unicast
    • 5.2.1.3 Multicast
  • 5.2.2 IP Header Validation
  • 5.2.3 Local Delivery Decision
  • 5.2.4 Determining the Next Hop Address
    • 5.2.4.1 IP Destination Address
    • 5.2.4.2 Local/Remote Decision
    • 5.2.4.3 Next Hop Address
    • 5.2.4.4 Administrative Preference
    • 5.2.4.5 Load Splitting
  • 5.2.5 Unused IP Header Bits: RFC-791 Section 3.1
  • 5.2.6 Fragmentation and Reassembly: RFC-791 Section 3.2
  • 5.2.7 Internet Control Message Protocol - ICMP
    • 5.2.7.1 Destination Unreachable
    • 5.2.7.2 Redirect
    • 5.2.7.3 Time Exceeded
  • 5.2.8 INTERNET GROUP MANAGEMENT PROTOCOL - IGMP
• 5.3 SPECIFIC ISSUES
  • 5.3.1 Time to Live (TTL)
  • 5.3.2 Type of Service (TOS)
  • 5.3.3 IP Precedence
    • 5.3.3.1 Precedence-Ordered Queue Service
    • 5.3.3.2 Lower Layer Precedence Mappings
    • 5.3.3.3 Precedence Handling For All Routers
  • 5.3.4 Forwarding of Link Layer Broadcasts
  • 5.3.5 Forwarding of Internet Layer Broadcasts
    • 5.3.5.1 Limited Broadcasts
    • 5.3.5.2 Directed Broadcasts
    • 5.3.5.3 All-subnets-directed Broadcasts
    • 5.3.5.4 Subnet-directed Broadcasts
  • 5.3.6 Congestion Control
  • 5.3.7 Martian Address Filtering
  • 5.3.8 Source Address Validation
  • 5.3.9 Packet Filtering and Access Lists
  • 5.3.10 Multicast Routing
  • 5.3.11 Controls on Forwarding
  • 5.3.12 State Changes
    • 5.3.12.1 When a Router Ceases Forwarding
    • 5.3.12.2 When a Router Starts Forwarding
    • 5.3.12.3 When an Interface Fails or is Disabled
    • 5.3.12.4 When an Interface is Enabled
  • 5.3.13 IP Options
    • 5.3.13.1 Unrecognized Options
    • 5.3.13.2 Security Option
    • 5.3.13.3 Stream Identifier Option
    • 5.3.13.4 Source Route Options
    • 5.3.13.5 Record Route Option
    • 5.3.13.6 Timestamp Option