Title of Invention

A METHOD FOR AUTOMATIC V6-IN-V4 TUNNEL CONFIGURATION USING RIPNG.

Abstract

This invention is related to automating the process of discovery of new IPv6 networks and configuration of v6-in-v4 tunnel between two Dual Stack routers belonging to two different IPv6 networks over a v4 backbone using RIPng. More particularly the present invention relates to a method for automatic v6-in-v4 tunnel configuration using ripng. This invention explains a method for automatic v6-in-v4 tunnel configuration using RIPNG comprising plurality of dual stack routers connected through IPv4 for providing IPv6 connectivity for their IPv6 nodes, the method comprising the steps of: at the dual stack router: triggering RIPng Request message when routing message which is sent by an IGP protocol running on IPv4 is received directly or indirectly from any router that joins the autonomous system; constructing RIPng request/reply with RTE entries associated with Metric OxFE and OxFD; encapsulating RIPng request/reply message in an IPv4 packet and transmitting it to a broadcast/multicast/unicast destination; and decapsulating IPv4 packet containing RIPng request/reply message after receiving it and processing of the same.

Full Text

FIELD OF INVENTION This invention is related to automating the process of discovery of new IPv6 networks and configuration of v6-in-v4 tunnel between two Dual Stack routers belonging to two different IPv6 networks over a v4 backbone using RIPng. More particularly, the present invention relates to a method for automatic v6-in-v4 tunnel configuration using RIPng. DESCRIPTION OF RELATED ART The [TRANS-MECH] explains manually configured tunnels and [6to4] describes automatic 6to4 tunneling. Using manual configuration, bi-directional IPv6-in-IPv4 tunnels have to be configured to reach each and every IPv6 network that attaches to the IPv4 backbone/infrastructure. 6to4 tunnels use a special prefix which leads to scalability and site re-numbering issues during transition and hence it is not widely recommended for use. But there is no prior method available till now to discover new IPv6 networks. Configured Tunneling (Refer to Figure.1) 1. At R1 1.2. Create a tunnel with source as R1 and destination as R2. 1.3. Add a static route in the IPv6 routing table to route IPv6 packets destined for R2's IPv6 network/hosts. 2. At R2, 2.2. Create a tunnel with source as R2 and destination as R1. 2.3. Add a static route in the IPv6 routing table to route IPv6 packets destined for R1's IPv6 network/hosts. 3. Any packets from IPv6 hosts belonging to R1 or R2 can now reach each other over the tunnel. Automatic Tunneling (Refer to Figure.2) 1. 6to4 IPv6 Address creation (Refer to Figure.3) Any isolated IPv6 domain can autonomously build its own globally unique IPv6 prefix. The globally unique IPv4 address of the domain border router is used for this purpose. 2. For communication among 6to4 sites 2.2. The egress router automatically creates a tunnel to the destination domain using the IPv4 endpoint is extracted from the destination IPv6 prefix. 2.3. For this to work, only the egress router has to be 6to4 capable. 3. This automatic tunneling happens for each and every packet getting routed between the 6to4 sites. There are following limitations to the existing art: 1. Manual Configuration method is tedious. 2. If no route to reach IPv6 destination is available, then packets are either discarded or dropped by Dual-Stack Border Router. 3. Dependency on v4 addresses is strongly discouraged. V6 addresses are meant to be dynamic and automatically configured. They should be independent of the v4 addresses. SUMMARY OF THE INVENTION The primary object of this invention is to invent a method for discovering route reachability to isolated IPv6 clouds that joins/attaches to IPv4 backbone / infrastructure. The IPv6 clouds and the IPv4 backbone should be part of the same autonomous system. IPv4 to IPv6 Transition is currently in the infant stage. Hence, many IPv6 networks are coming up and there is need for connectivity between these clouds through IPv4 backbone. For this IPv6-in-IPv4 tunnels between the clouds establish the IPv6 connectivity transparently to the IPv6 nodes in the clouds over IPv4 backbone / infrastructure. The invention satisfies the following criteria: • The v6 address need not have any relation with the v4 address. • The Tunnel formation should be completely automatic. No reconfiguration or support of legacy v4 routers required. The invention deals with addition of information in RIPng packet that can establish an automatic tunnel between two dual stack routers in the v4 backbone. The dual-stack routers must have public v6 and v4 addresses. The v6 addresses of the dual-stack routers are independent of the corresponding v4 addresses unlike in 6to4. The Dual Stack routers and the v4 backbone should be a part of the same Autonomous System with a common Interior Gateway Protocol. All the Dual Stack Routers wanting to share information must have RIPng running. The method uses IPv6-in-IPv4 encapsulation/decapsulation to send/receive the RIPng messages defined in this invention. Accordingly the present invention relates to a method for automatic v6-in-v4 tunnel configuration using RIPng comprising two or more Dual Stack Routers connected through IPv4 for providing IPv6 connectivity for their IPv6 nodes, the method comprising the steps of: At the Dual Stack Router: ? Triggering RIPng Request message when Routing Message (sent by an IGP protocol running on IPv4) is received (directly or indirectly) from any Router that joins the autonomous system ? Constructing RIPng Request/Reply with RTE entries associated with Metric OxFE and OxFD ? Encapsulating RIPng Request/Reply message in an IPv4 packet and transmitting it to a broadcast/multicast/unicast destination ? Decapsulating IPv4 packet containing RIPng Request/Reply message after receiving it and processing of the same. Accordingly the present invention further comprising, RIPng instructing the data link layer abstraction to create IPv6-in-IPv4 tunnel with the pair Accordingly the present invention further comprising, addition of Route entry for an IPv6 host/network after creating the tunnel using the IPv6 Prefix of the sender extracted from RTE in the RIPng packet. A new Dual Stack router which is part of one or more v4 and/or v6 network comes up and gets attached to a v4 backbone. The said new Dual Stack router sends a Routing Response to the v4 backbone. The v4 routers add new destination entries in their respective routing tables and the update is conveyed to all the routers in the autonomous system. An existing dual-stack border router notices a new destination entry in its routing table and sends the new RIPng request packet with the v6 header encapsulated in a v4 header to new Dual Stack router through the v4 backbone where the said packet is sent to new Dual Stack router using broadcast, multicast, or unicast destination address. On receiving the RIPng packet, new Dual Stack router comes to know of the v4 as well as the v6 global addresses of the existing dual-stack border router and interprets existing dual-stack border router's Dual Stack Capability. New Dual Stack router sends unicast new RIPng Response packet with the v6 header encapsulated in a v4 header to existing dual-stack border router. On receiving the RIPng packet, existing dual-stack border router comes to know of the v4 as well as the v6 global addresses of new Dual Stack router, as well as the v6 networks reachable through new Dual Stack router thereby interpreting new Dual Stack router's Dual Stack capability. When IPv4 or IPv6 addresses of either existing dual-stack border router or new Dual Stack router gets changed, new RIPng packets are sent again to re-establish the tunnel. The dual-stack routers have public v6 and v4 addresses. The Dual Stack routers and the v4 backbone is a part of the same autonomous system with a common Interior Gateway Protocol. All the Dual Stack Routers wanting to share information must have RIPng running. These and other objects, features and advantages of the present invention will become more readily apparent from the detailed description taken in conjunction with the drawings and the claims. BRIEF DESCRIPTION OF THE ACCOMPANYING DRAWINGS Figure 1 shows as how two IPv6 networks are connected to each other using Configured Tunneling. Figure 2 shows how tunneling happens between two IPv6 networks (6to4 sites) connected over IPv4 backbone. Figure 3 depicts forming IPv6 address for hosts within a 6to4 site using 6to4 prefix and IPv4 address of the Dual-Stack Border Router to which they are connected. Figure 4 shows a typical RIPng packet that carries the Routing Information. Figure 5 shows the format of an RTE (Routing Table Entry) that contains the routing information. Figure 6 shows a RIPng Request Packet. Figure 7 shows a RIPng Response packet. Figure 8 shows an example network where two isolated IPv6 networks are connected over IPv4 backbone. Figure 9 shows the operation of the method disclosed in this invention. Figure 10 shows the proposed new RIPng Request packet for the entire v6 routing table. Figure 11 shows the proposed new RIPng Response packet DETAILED DESCRIPTION OF THE INVENTION The preferred embodiments of the present invention will now be explained with reference to the accompanying drawings. It should be understood however that the disclosed embodiments are merely exemplary of the invention, which may be embodied in various forms. The following description and drawings are not to be construed as limiting the invention and numerous specific details are described to provide a thorough understanding of the present invention, as the basis for the claims and as a basis for teaching one skilled in the art how to make and/or use the invention. However in certain instances, well-known or conventional details are not described in order not to unnecessarily obscure the present invention in detail. A number of IPv4 to IPv6 Transition mechanisms like Tunneling, Translation and Dual-Stack Transition Mechanisms are currently being used to enable IPv4 and IPv6 to co-exist and co-work during the transition phase. Tunneling is the most common transition mechanism deployed world-wide. There is a growing awareness among the standards committees like IETF, 3GPP and 3GPP2 to make efforts to develop and deploy methods to automate the process of establishing IPv6-in-IPv4 tunnels so that isolated IPv6 networks or hosts can obtain connectivity to other such IPv6 networks or hosts over IPv4 backbone networks with very minimal changes to existing protocols and equipments. In this invention we propose a method to automate the discovery of new IPv6 networks and to automatically configure v6-in-v4 tunnel between two Dual Stack routers belonging to two different IPv6 networks over a v4 backbone using RIPng. Figure 1 shows as how two IPv6 networks are connected to each other using Configured Tunneling. R1 and R2 are two Dual-Stack Border Routers attached to their respective IPv6 networks. IPv4 is the backbone over which R1 and R2 communicate. Figure 2 shows as how tunneling happens between two IPv6 networks (6to4 sites) connected over IPv4 backbone. R1 and R2 are two Dual-Stack Border Routers attached to their respective IPv6 networks. R1 and R2 support 6to4 tunneling. Figure 3 depicts forming IPv6 address for hosts within a 6to4 site using 6to4 prefix and IPv4 address of the Dual-Stack Border Router to which they are connected. The Dual-Stack Border Router supports 6to4 tunneling. Figure 4 shows a typical RIPng packet that carries the Routing Information. Figure 5 shows the format of an RTE (Routing Table Entry) that contains the routing information. Figure 6 shows a RIPng Request Packet with the following entries: Command =1 (Request) Version = 1 IPv6 prefix = :: Route Tag = 0 Prefix Len = 0 Metric = 0x10 The Metric in RIPng is between 0 and 15. Metric=0x10 is a special case when the entire routing table is required. IPv6 prefix = :: refers to the unspecified address with all bits as zero. Figure 7 shows a RIPng Response packet with the following entries. Command =2 (Response) Version = 1 Metric=OxFF signifies that IPv6 prefix in the corresponding RTE is a next hop address. Figure 8 shows an example network where two isolated IPv6 networks are connected over IPv4 backbone. Figure 9 shows the operation of the method disclosed in this invention. It depicts control and data message flow. Figure 10 shows the proposed new RIPng Request packet for the entire v6 routing table. • The message carries the global v4 as well as the global v6 address of the sender. • ::100.21.24.1 is the sender's v4 address packed/formatted in a v6 address for placing it in the RTE. • Metric=OxFD signifies that IPv6 prefix in the corresponding RTE contains the v4 address of the sender in the last 4 bytes. • Metric=OxFE signifies that IPv6 prefix in the corresponding RTE is the v6 address of the sender. • Metric=OxFF with v6 address as an unspecified address signifies a request for the entire routing table. Metric value OxFF is already defined and used in RIPng. Metric values OxFE and OxFD are defined as part of this invention. Figure 11 shows the proposed new RIPng Response packet • The new RIPng response packet carries the global v4 as well as the global v6 address of the sender along with the RTE's for various v6 networks present in the v6 routing table of the sender. • ::100.21.25.1 is the sender's v4 address packed/formatted in a v6 address for placing it in the RTE. • Metric=OxFD signifies that the IPv6 prefix in the corresponding RTE contains the v4 address of the sender in the last 4 bytes. • Metric=OxFE signifies that the IPv6 prefix in the corresponding RTE is the v6 address of the sender. • Metric=OxFF signifies that IPv6 prefix in the corresponding RTE is the next-hop address. • The last RTE in the Response packet shown contains a destination with metric=2. Metric values OxFE and OxFD are defined as part of this invention The Figure.4 depicts an example scenario where this method is helpful. Following assumptions have been made: • The dual-stack routers must have public v6 and v4 addresses. • The Dual Stack routers and the v4 backbone should be a part of the same Autonomous System with a common Interior Gateway Protocol. • All the Dual Stack Routers wanting to share information must have RIPng running. The following is the step-by-step operation of the invention: (Refer to Figure.8 and Figure.9) 1. A new Dual Stack router R2 (part of one or more v4 and/or v6 network) comes up and gets attached to a v4 backbone. 2. R2 sends a Routing Response to the v4 backbone. 3. The v4 routers add a new destination entry(ies)( v4 network(s) of R2) in their respective routing tables and the update is conveyed to all the routers in the Autonomous System. 4. R1 notices a new destination entry(ies) (v4 network(s) of R2) in its routing table and sends the new RIPng request packet (with the v6 header encapsulated in a v4 header) to R2 through the v4 backbone. This packet may be sent to R2 using broadcast, multicast, or unicast destination address. 5. On receiving the RIPng packet, R2 comes to know of the v4 as well as the v6 global addresses of R1. It interprets this RVs Dual Stack Capability. 6. R2 sends unicast new RIPng Response packet (with the v6 header encapsulated in a v4 header) to R1. 7. On receiving the RIPng packet, R1 comes to know of the v4 as well as the v6 global addresses of R2, as well as the v6 networks reachable through R2. It interprets this as R2's Dual Stack capability. Hence, both R1 and R2 come to know of each other's current v4 and v6 global addresses. This leads to the establishment of an automatic v6 in v4 tunnel between R1 and R2. When IPv4 or IPv6 addresses of either R1 or R2 get changed, new RIPng packets can be sent again to re-establish the tunnel. It will also be obvious to those skilled in the art that other control methods and apparatuses can be derived from the combinations of the various methods and apparatuses of the present invention as taught by the description and the accompanying drawings and these shall also be considered within the scope of the present invention. Further, description of such combinations and variations is therefore omitted above. It should also be noted that the host for storing the applications include but not limited to a microchip, microprocessor, handheld communication device, computer, rendering device or a multi function device. Although the present invention has been fully described in connection with the preferred embodiments thereof with reference to the accompanying drawings, it is to be noted that various changes and modifications are possible and are apparent to those skilled in the art. Such changes and modifications are to be understood as included within the scope of the present invention as defined by the appended claims unless they depart therefrom. REFERENCES: [IPv6] Deering S. and R. Hinden, "Internet Protocol, Version 6 (IPv6) Specification", RFC 2460, December 1998. TRANS-MECH] Gilligan, R., Nordmark, E, "Transition Mechanisms for IPv6 Hosts and Routers", RFC 2893, August 2000. [6to4] Carpenter, B., Moore, K, "Connection IPv6 Domains via IPv4 Clouds", RFC 3056, February 2001. [RIPng] G. Malkin, R. Minnear, "RIPng for IPv6", RFC 2080, January 1997. GLOSSARY OF TERMS AND DEFINITIONS THEREOF IPv4 Internet Protocol Version 4 IPv6 Internet Protocol Version 6 IPv6-ln-IPv4 IPv6 packets encapsulated in an IPv4 packet RIPng Routing Information Protocol for Next Generation (IPv6) RTE Routing Table Entry (for RIPng) WE CLAIM 1. A method for automatic v6-in-v4 tunnel configuration using RIPNG comprising plurality of dual stack routers connected through IPv4 for providing IPv6 connectivity for their IPv6 nodes, the method comprising the steps of: at the dual stack router: (a) triggering RIPng Request message when routing message which is sent by an IGP protocol running on IPv4 is received directly or indirectly from any router that joins the autonomous system; (b) constructing RIPng request/reply with RTE entries associated with Metric OxFE and OxFD; (c) encapsulating RIPng request/reply message in an IPv4 packet and transmitting it to a broadcast/multicast/unicast destination; and (d) decapsulating IPv4 packet containing RIPng request/reply message after receiving it and processing of the same. 2. A method as claimed in claim 1 wherein a new Dual Stack router which is part of one or more v4 and/or v6 network comes up and gets attached to a v4 backbone. 3. A method as claimed in claim 1 wherein the said new Dual Stack router sends a Routing Response to the v4 backbone. 4. A method as claimed in claim 1 wherein the v4 routers add new destination entries in their respective routing tables and the update is conveyed to all the routers in the autonomous system. 5. A method as claimed in claim 1 wherein an existing dual-stack border router notices a new destination entry in its routing table and sends the new RIPng request packet with the v6 header encapsulated in a v4 header to new Dual Stack router through the v4 backbone where the said packet is sent to new Dual Stack router using broadcast, multicast, or unicast destination address. 6. A method as claimed in claim 1 wherein on receiving the RIPng packet, new Dual Stack router comes to know of the v4 as well as the v6 global addresses of the existing dual-stack border router and interprets existing dual-stack border router's Dual Stack Capability. 7. A method as claimed in claim 1 wherein new Dual Stack router sends unicast new RIPng Response packet with the v6 header encapsulated in a v4 header to existing dual-stack border router. 8. A method as claimed in claim 1 wherein on receiving the RIPng packet, existing dual-stack border router comes to know of the v4 as well as the v6 global addresses of new Dual Stack router, as well as the v6 networks reachable through new Dual Stack router thereby interpreting new Dual Stack router's Dual Stack capability. 9. A method as claimed in claim 1 wherein when IPv4 or IPv6 addresses of either existing dual-stack border router or new Dual Stack router gets changed, new RIPng packets are sent again to re-establish the tunnel. 10. A method as claimed in claim 1 wherein the dual-stack routers have public v6 and v4 addresses. 11. A method as claimed in claim 1 wherein the Dual Stack routers and the v4 backbone is a part of the same autonomous system with a common Interior Gateway Protocol. 12. A method as claimed in claim 1 wherein all the Dual Stack Routers wanting to share information must have RIPng running. 13. A method as claimed in claim 1 further comprising, RIPng instructing the data link layer abstraction to create IPv6-in-IPv4 tunnel with the pair . 14. A method as claimed in claim 1 further comprising, addition of route entry for an IPv6 host/network after creating the tunnel using the IPv6 prefix of the sender extracted from RTE in the RIPng packet. 15. A method for automatic v6-in-v4 tunnel configuration using RIPNG substantially described particularly with reference to the accompanying drawings. Dated this 22nd day of December 2005

Documents:

1491-CHE-2004 AMENDED PAGES OF SPECIFICATION 19-11-2012.pdf

1491-CHE-2004 AMENDED CLAIMS 19-11-2012.pdf

1491-CHE-2004 EXAMINATION REPORT REPLY RECEIVED 19-11-2012.pdf

1491-CHE-2004 FORM-1 19-11-2012.pdf

1491-CHE-2004 FORM-13 19-06-2006.pdf

1491-CHE-2004 FORM-13 19-11-2012.pdf

1491-CHE-2004 FORM-5 19-11-2012.pdf

1491-CHE-2004 OTHER PATENT DOCUMENT 19-11-2012.pdf

1491-che-2004-abstract.pdf

1491-che-2004-claims.pdf

1491-che-2004-correspondnece-others.pdf

1491-che-2004-description(complete).pdf

1491-che-2004-description(provisional).pdf

1491-che-2004-drawings.pdf

1491-che-2004-form 1.pdf

1491-che-2004-form 13.pdf

1491-che-2004-form 26.pdf

1491-che-2004-form 5.pdf