7.1. Implementation of the TCP/IP protocols7.1.1. Terminal equipment7.1.2. Routers7.1.3. IP layer architecture7.2. Internet addressing7.2.1. Notation7.2.2. Special IPv4 addresses7.2.3. IPv4 class addressing7.2.3.1. Usage of the netmask7.2.3.2. Variable length network masks7.2.3.3. Classfull address drawback7.2.4. Hierarchical addressing7.2.4.1. Classless Internet domain routing (CIDR)7.2.4.2. Aggregation rules7.2.4.3. Example of allocation hierarchy7.2.5. Special IPv4 prefixes and addresses7.2.5.1. Addresses for private networks (RFC 1597)7.2.6. Special IPv6 addresses and prefixes7.3. The IPv4 protocol (RFC 791, RFC 1122)7.3.1. Format of IPv4 datagrams7.3.1.1. Version7.3.1.2. Internet header length7.3.1.3. Type of service7.3.1.4. Total length7.3.1.5. Fragmentation7.3.1.6. Time to Live7.3.1.7. Protocol7.3.1.8. Checksum (RFC 1071, RFC 1141)7.3.1.9. Source and destination addresses7.3.1.10. Options7.4. The ICMP (Internet Control Message Protocol) (RFC 792)7.4.1. The message cannot reach its destination7.4.2. Expired TTL and the traceroute program7.4.2.1. Limitation of ICMP traffic7.4.2.2. Loose source routing option7.4.3. Quench source7.4.4. Redirection indication7.4.5. Echo/the ping command7.4.5.1. Route recording option7.4.5.2. Broadcast address7.4.6. Netmask request /reply to netmask (RFC 950)7.4.7. Information about routers (RFC 1256)7.4.8. MTU discovery (RFC 1191)7.5. The IPv6 protocol7.5.1. Format of IPv6 datagrams7.5.2. The ICMPv6 protocol7.6. Tunnels7.6.1. Architecture7.6.2. Encapsulations7.6.2.1. Simple encapsulation7.6.2.2. Generic routing encapsulation7.7. Configurations7.7.1. Configuration of a Unix station7.7.2. Visualization7.7.3. Configuration7.8. Configuration of a Cisco router7.8.1. Visualization7.8.2. Configuration7.9. IPv4 and multicast7.9.1. Format of multicast addresses7.9.2. The IGMPv2 protocol (RFC 3376)