INTRODUCTION   4 

     Why a New Version?   4 
     CIDR: Classless Interdomain Routing   6 
     Major Changes From IPv4   8 
     Resources   9 
     Header Formats   10 
     DNS Support   11 
     IPv6 Addresses   12 
        Unspecified Address   14 
        Loopback Address   14 
        IPv4-Mapped IPv6 Address   14 
        IPv4-Compatible IPv6 Address   15 
        Interface IDs   15 
        Link-Local Address   16 
        Site-Local Address   16 
        Aggregatable Global Unicast Addresses   17 
     6bone   19 

APPLICATION PROGRAMMING INTERFACE CHANGES   20 

     Big Picture   20 
     sockaddr_in6 Structure   22 
     Address Conversion Functions   25 
        inet_pton Function   27 
        inet_ntop Function   28 
        gethostbyname Function   29 
        gethostbyname2 Function   29 
        getaddrinfo Function   34 
        getnameinfo Function   36 
     New Socket Options   39 
     Converting IPv4 Applications to IPv6   42 

TRANSITION MECHANISMS   43 

     The IPv4 Internet   43 
     Adding IPv6/IPv4 hosts   45 
        IN6_IS_ADDR_V4MAPPED Macro   50 
        IPV6_ADDRFORM Socket Option   51 
     Automatic Tunneling   53 
     Configured Tunnels   57 
     IPv6 Routing Table Example   57 
     Longest Prefix Match   59 

IPv6 PROTOCOL   60 

     IPv6 Header   60 
     Class   61 
     Flow Label   62 
     Payload Length   63 
     Next Header   63 
     Hop Limit   63 
     Extension Headers   65 
     Hop-by-Hop and Destination Options   66 
     Routing Header   70 
     Fragment Header   74 
     Path MTU Discovery   76 
     Authentication Header   79 
     Encapsulating Security Payload Header   80 

UPPER-LAYER ISSUES   81 

     Checksums   81 
     Other Issues   85 

ICMPv6: INTERNET MESSAGE CONTROL PROTOCOL   86 

     Introduction   86 
     Destination Unreachable   89 
     Packet Too Big   90 
     Time Exceeded   90 
     Parameter Problem   91 
     Echo Request/Reply   92 

MULTICASTING   93 

     Introduction   93 
     ICMP Group Membership Messages   102 
     Multicast Routing   104 
     Multicast API   106 

NEIGHBOR DISCOVERY   109 

     Introduction   109 
     Neighbor Solicitation   114 
     Neighbor Advertisement   116 
     Redirect   118 
     Router Solicitation   120 
     Router Advertisement   121 
     Neighbor Unreachability Detection   126 
     Duplicate Address Detection   128 

OTHER TOPICS   130 

     Anycasting   130 
     Mobility   136 

Further Reading   141