CSE 8343 Group 3 Advanced OS

1. CSE 8343 Group 3 Advanced OS Inter Operability Between IPv4 and IPv6 Team Members Aman Preet Singh Rohit Singh Nipun Aggarwal Chirag Shah Eugene Novak

2. CSE 8343 Group 3 Advanced OS Why IPv6? Problems in IPv4 • Shortage of IP addresses • Variable header size • No support for Qos • Security • Not Plug n Play IPv6 advantage over IPv4 • Scalability • Fixed Header • Quality of Service • Security • Plug and play • Optimization

3. CSE 8343 Group 3 Advanced OS Why Interoperability ? • IPv6 is a better option • IPv4 is omnipresent • Ipv6 is not an upgrade for IPv4 • Moral of the story • Interoperability between IPv4 and IPv6 is compulsory

4. IPv4 IPv6 IPv4 IPv4 IPv4 IPv4 IPv4 IPv4 IPv6 IPv4 IPv6 IPv4 IPv4 IPv4 IPv6 IPv6 IPv6 IPv4 IPv6 IPv4 IPv6 IPv6 IPv6 IPv4 IPv6 IPv4 IPv6 IPv6 IPv6 IPv6 CSE 8343 Group 3 Advanced OS Transition Scenarios

5. Scenario A: IPv6 nodes needs to communicate with IPv4 nodes • Solution: Use Dual IP Stacks • The hosts implement both protocols • UseIPv4 compatible IPv6 addresses CSE 8343 Group 3 Advanced OS Methods for Interoperability: Dual IP stack • Disadvantages: • Does not addresses the problem of shortage of IP addresses • Is burdensome for the routers • Solution: • Network Address Translator - Protocol Translator (NAT-PT) • Dual Stack Transition Mechanism, or DSTM

6. CSE 8343 Group 3 Advanced OS Methods for Interoperability: Tunneling • Scenario B: Islands of IPv6 need IPv4 network to communicate • Solution: Use Tunneling • Append IPv4 header to IPv6 packet • Route the packet to a host/router having dual • IP stacks

7. CSE 8343 Group 3 Advanced OS Methods for Interoperability: Tunneling • Terminology: • IPv4-only node: A host or router that implements only IPv4 • IPv6/IPv4 node: A host or router that implements both IPv4 • and IPv6 • IPv6-only node: A host or router that implements only IPv6 • Tunneling can be used in a variety of ways: • Router-to-Router -- IPv6/IPv4 routers interconnected by • an IPv4 infrastructure can tunnel IPv6 packets between • themselves • Host-to-Router -- IPv6/IPv4 hosts can tunnel IPv6 packets • to an intermediary IPv6/IPv4 router that is reachable via • an IPv4 infrastructure • Host-to-Host -- IPv6/IPv4 hosts that are interconnected by • an IPv4 infrastructure can tunnel IPv6 packets between • themselves • Router-to-Host -- IPv6/IPv4 routers can tunnel IPv6 packets • to their final destination IPv6/IPv4 host

8. CSE 8343 Group 3 Advanced OS Methods for Interoperability: Tunneling • Techniques of Tunneling: • Configured Tunneling • Used for router-to-router and host-to-router tunneling • The endpoint of the tunnel is different from the • destination of the packet being tunneled • The tunnel endpoint address must be determined from • configuration information on the node performing the • tunneling • Automatic Tunneling • Used for host-to-host and router-to-host tunneling • The endpoint of the tunnel is same as the destination • of the packet being tunneled • IPv4 compatible addresses are used • IPv6 packets that are not addressed to an IPv4-compatible • address can not be tunneled using automatic tunneling

9. Disadvantages of Tunneling: • Not scalable • Not feasible for dial up users • Solution: • 6over4 • 6to4 • Tunnel Brokering CSE 8343 Group 3 Advanced OS Methods for Interoperability: Tunneling

10. C B A NAT-PT IPv6 IPv4 CSE 8343 Group 3 Advanced OS Interoperability Techniques: NAT-PT • Network Address Translation - Protocol Translation • Uses a pool of V4 addresses for assignment to V6 nodes • Requires no change at the end nodes • Protocol translation is done using SIIT protocol (rfc 2765) • Maintains session information • How NAT-PT works: • IPv6 Node A wants to communicate with the IPv4 Node C • Node A creates a packet as following: • Source Address, SA=FEDC:BA98::7654:3210 and Destination • Address, DA = PREFIX::132.146.243.30

11. CSE 8343 Group 3 Advanced OS Interoperability Techniques: NAT-PT • How NAT-PT works: continued …… • NAT-PT locally allocates an address (e.g: 120.130.26.10) • from its pool of addresses • The packet is translated to IPv4 • The translation parameters are cached for the duration • of the session and the IPv6 to IPv4 mapping is retained • by NAT-PT • Thus resulting IPv4 packet has SA=120.130.26.10 and • DA=132.146.243.30 • Disadvantage: • Pool of V4 addresses assigned for translation purposes is • exhausted

12. CSE 8343 Group 3 Advanced OS Interoperability Techniques: DSTM • Dual Stack Transition Mechanism • Provides interoperability in an IPv6 dominant network • Transition mechanism and not a protocol • Main Components • DSTM server • DSTM client • DSTM border router DSTM Server B A DSTM Border Router IPv4 IPv6

13. Tunnel Server User Tunnel Broker Tunnel Server Tunnel Server CSE 8343 Group 3 Advanced OS Interoperability Techniques: Tunnel Brokering • Tunnel Brokering • Allows IPv6 isolated islands to communicate through • IPv4 network • Ideal choice for small IPv6 site and hosts • Dedicated servers configure tunnels client’s behalf • The tunnel broker model has the following components • Tunnel Broker • Tunnel Server • Dual stack Host (user)

14. CSE 8343 Group 3 Advanced OS Interoperability Techniques: Tunnel Brokering • Using the Tunnel Broker • The Client • Submits the request to access the services of the • Tunnel Broker • Provides its IPv4 address • The Tunnel Broker • Assigns a Tunnel Server to the client • Assigns IPv6 global addresses to the tunnel end points • Assigns a lifetime to the tunnel • Sends the configuration information to the client • Tunnel Management • Lifetime Timer • Using some sort of keep alive mechanism • Make the Tunnel Server periodically deliver to the Tunnel • Broker the IPv6 traffic statistics for every active tunnel

15. CSE 8343 Group 3 Advanced OS Interoperability Techniques: 6to4 • 6to4 • Allows IPv6 sites to communicate with each other over • the IPv4 network without explicit tunnel setup • Typically implemented in border routers • At least one IPv4 address required for the site • IPv6 domains build their own IPv6 prefix based on the IPv4 • address of the border router • The border router can easily tunnel the packet due to the • use of prefixes

16. CSE 8343 Group 3 Advanced OS Other Interoperability Techniques • 6over4 • 6over4 is an elegant solution for interconnecting isolated IPv6 • hosts in an IPv4 site. IPv6 multicast is implemented over IPv4 • multicast. Using IPv6 multicast, IPv6 nodes can then use • Neighbor Discovery to configure themselves. • IPv4 multicast is not generally available on all networks, • and there are scalability issues with this approach. • Dual Stack ALG • Dual-stack servers are used as proxies to perform protocol • translation with one proxy server per application (http, ftp, • smtp, etc) • Very few IPv4 addresses are required (they are only needed • for the proxies)and • protocol translation step may not be such a large price to pay • in situations where firewalls and proxy server already exist, • which is the case in many LAN

17. CSE 8343 Group 3 Advanced OS Questions or Comments