Extra Recommended Projects Last modified Gogo6 Tunnel with Router Advertisements gogoCLIENT IPv6 Backbone Freenet6 Tunnel Broker Native IPv6 IPv6 packets inside IPv4 packets IPv6 RA Packet SLAAC (Stateless Address Autoconfiguration) RA packet specifies first 64 bits of address & gateway address Host generates the last 64 bits gogoCLIENT IPv6 RA Packet Router Advertisement (RA) Scanning a LAN IPv4-to-IPv6 Reverse Proxy IPv4-only Web server IPv6-to- IPv4 Reverse Proxy IPv4 Legacy IPv4 Clients IPv6 Clients IPv6 haproxy Linux proxy and load-balancer This configuration listens on IPv6 for clients and proxies to IPv4 Proxy Listening on IPv6 Port 80 for HTTP Port 442 for HTTPS Proxy in Action Put the IPv6 address in the browser Press Enter CCSF Web page opens Not an IPv4 Connection Ch 4: IPv6 Advanced Topics Topics Multihoming Multicast QoS Mobile IPv6 Jumbograms DHCP Prefix renumbering 4.1: Multihoming Multiple addresses on the same node Advantages: Multiple paths to the Internet for fault-tolerance or load-balancing QoS differentiation Security policy enforcement Costs: Either the Internet backbone needs multiple routes to the host, or The node must sort out the traffic Provider-Independent Addresses IP addresses dont change when you change ISPs Easiest for end users to manage Fragments and increases the Internet backbone routing tables ARIN will give qualifying companies a /48, provider-independent Link Ch4a Live BGP Updates Link Ch 4b IPv6 BGP table has 2000 routes at present, but it is growing Link Ch 4c Site Multihoming by IPv6 Intermediation (SHIM6) Specification A way to limit IPv6 BGP table growth Splits layer 3 into sublayers iClicker Questions Which of these encapsulates IPv6 packets inside IPv4 packets? A.Proxy B.Tunnel C.Router D.Switch E.SLAAC What packet tells a host where the IPv6 default gateway is? A.ARP B.ND C.SLAAC D.RA E.DNS Which item makes it safe and easy to make an IPv4 Web server available via IPv6? A.Proxy B.Tunnel C.Router D.Switch E.SLAAC What protocol provides routing updates on the Internet backbone? A.OSPF B.BGP C.SLAAC D.RA E.DNS 4.2: IPv6 Multicast IPv4 Broadcast packets are read by every node that receives them Multicast packets are only read by nodes that have subscribed to that multicast group Multicast Advantages Sender only needs to create one packet for many receivers Less bandwidth consumption Sender doesnt need to know or remember how many listeners there are Typical uses: streaming audio or video, router updates, Ghosting hard drives ARP Broadcast in IPv4 Where is the gateway? Neighbor Discovery in IPv6 What other address does FE80::4DF2: 54C8:B8C7:113A have? Takes the low-order 24 bits of this address (C7:113A) Appends them to the well- known solicited node multicast prefix, FF02:0:0:0:0:1:FF00::/104 Sends Neighbor Solicitation message to that solicited node multicast address FF02::1:FFC7:113A Well-Known Multicast Addresses Link-local scope FF02::1 All Nodes FF02::2 All Routers FF02::1:2 All DHCP Agents Multicast Listener Discovery (MLD) A Protocol used by interfaces to join and leave multicast groups Routers keep track of these groups for each interface on which they forward packets Uses Multicast Listener Query and Multicast Listener Report packets Multicast Address format Always starts with FF Flags are 0 for well-known addresses Scope Bits Demonstration Using IPCONFIG to find the Interface ID in Windows 7 (%12) IPv6 address ends in b225 Demonstration Sniff on the correct adapter in Wireshark IPv6 address ends in b225 Ping Local Interface ff01::1 Ping Link-Local Interface ff02::1 4.3 IPv6 Quality of Service (QoS) QoS includes several techniques to adjust performance for different types of traffic Streaming media need low latency but can tolerate some packet loss File transfer can tolerate latency but not packet loss IPv6 Advantages for QoS (not fully implemented yet) End-to-end addressing; no need for NAT Simpler header Larger packet sizes No in-route fragmentation No broadcast & more efficient multicast A new Flow Label field and larger Traffic Class field in the main IPv6 header 4.4 Mobile IPv6 (MIPv6) MIPv6 Tems Mobile Node (MN). A node using MIPv6 to change its point of network attachment Home Address (HoA). The permanent, routable unicast address of the MN Home Link. The link on which the MNs HoA is defined Foreign Link. Any link except the home link Care-Of Address (CoA). A routable unicast address used by the MN on a foreign link Correspondent Node (CN). A peer with which the MN is communicating More MIPv6 Terms Home Agent (HA). A router on the MNs Home Link with which the MN registers its CoA and which forwards traffic to and from the MN at its CoA Route optimization. Direct communications between a MN and CN without involving a HA 4.5 Jumbograms With an Extension Header, packets larger than 65,536 bytes are allowed Up to 4 GB But they will only become practical when networks handle packet sizes that big (not yet) 4.6 Address Selection IPv6 interfaces have many addresses, so it is not obvious how to select from the available source addresses (or even destination addresses) when sending a packet The selection process is common-sense; use the smallest scope, avoid deprecated addresses, etc. 4.7 Dynamic Host Configuration Protocol (DHCP) for IPv6 SLAAC doesnt deliver DNS server info DHCP is Stateful, and requires a server Three primary configuration options are available for IPv6 interfaces: 1. Use autoconfiguration and not DHCPv6. 2. Use DHCPv6 and not autoconfiguration. 3. Get an address with autoconfiguration and then use DHCPv6 to retrieve additional information. 4.8 IPv6 Prefix Renumbering When you change ISPs, you need to update: Manually assigned addresses for interfaces on routers Routing information and link prefixes advertised by routers Addresses on routers, firewalls, and packet filters used for access control or ingress filtering Addresses assigned to interfaces with stateless address autoconfiguration Addresses and other information provided by DHCPv6 DNS records (primarily AAAA and PTR records, as well as DNSSEC) All other instances of addresses in applications, command sequences, configuration files, and elsewhere. iClicker Questions The well-known solicited node multicast prefix is FF02:0:0:0:0:1:FF00::/104. How many addresses are in that range? A.2^8 (256) B.2^16 (65536) C.2^24 (16.7 million) D.2^32 (4 billion) E.Some other number Which technique allows a person to maintain constant connections to Web servers while travelling from one LAN to another? A.MIPv6 B.Jumbograms C.SLAAC D.Anycast E.ND The first 8 bits of a multicast IPv6 address are always 1. What is the correct specifier of this address range? A /8 B.F000::/8 C.FF00::/8 D.FFFF::/8 E.Something else How many bits of the sought address are specified in a solicited node multicast address? A.8 B.24 C.64 D.128 E.Some other number What type of packets are used by nodes to subscribe to IPv6 multicast groups? A.ARP B.ND C.MLD D.RS E.IGMP