I2RS D. Liu
Internet-Draft China Mobile
Intended status: Informational July 15, 2013
Expires: January 16, 2014

I2RS use case for IPv6 transition
draft-liu-i2rs-ipv6-use-case-00

Abstract

This document discusses the use cases of I2RS in IPv4/IPv6 transition scenario.

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Table of Contents

1. Introduction

I2RS working group is chartered to define an interface to the routing system. This interface can be used to read topology and forwarding information of the routing system. This document discusses the use cases of I2RS in IPv4/IPv6 transition scenario.

2. Conventions used in this document

RIB: Routing Information Base

I2RS: Interface to Routing System

3. Use case of I2RS in IPv4/IPv6 transition scenario

3.1. I2RS use case for IPv4/IPv6 dual-stack network

There are several different ways for IPv4/IPv6 transition. For example, dual-stack is one popular technology to enable IPv4 to IPv6 transition. In dual-stack network, every router has both IPv4 and IPv6 IP stack running on it. The IPv4 and IPv6 protocol stack running on the dual-stack router normally work independently from each other although they share the same physical resources in the dual-stack router(CPU,memory etc). There are two different views of the dual-stack network from the IPv4 or IPv6 perspective. There are different set of routing information base for IPv4 and IPv6. In most cases, the IPv4 and IPv6 network need to have the same topology and forwarding state since they normally serves for the same dusal-stack host.

			   	   




                             +------------+
                             | Dual-stack |
                     +-------|   Router   |-------
        	          /        +------------+        \
  		       +----------+                         +-----------+
+----+       |Dual-stack|                         | Dual-stack|
|Host|-------|  Router  |                         |  Router   |
+----+       +----------+                         +-----------+
                  \                                 | 
                   \         +------------+        /
                    +--------| Dual-stack |-------+
                             |   Router   |
                             +------------+                                   	    		
  	

Figure 1. IPv4/IPv6 Dual-stack network for IPv4/IPv6 transition

It is a big challenge for the operators to operate dual-stack network, there are several reasons: 1. The network operation and management team may not familiar with IPv6. They have to learn new knowledge and new tools for IPv6. 2. There are two separate domains of the IPv4 and IPv6 network, the trouble shooting will become much more complex than single stack network. 3. Since the IPv4 and IPv6 stack share a single physical router, the problem of one protocol stack may spread to the other stack.

With I2RS, it can help the network operator to maintain a consistent view of both the IPv4 and IPv6 network in real time. The network operator can even configure the IPv6 network based on the existing IPv4 network and make the IPv4 network and the IPv6 have the same topology and forwarding state. This will reduce the complexity of operation and management and help the network operator discovery the in-consistent between the IPv4 and IPv6 network quickly.

3.2. I2RS use case in IPv4 and IPv6 translation scenario

In IPv4 and IPv6 translation scenario, the IPv4/IPv6 network's packets will be translated in to IPv4/IPv6 network's packets and vice versa. It is difficult for the network management system to get a consistent view of the translated network.

			   	   			                                 		                    			                         		              	          
    		      +--------------+                       +----------------+ 
 +----+       |              |   +---------------+   |                |    
 |Host|-------|IPv4/6 network|---|Translation box|---| IPv6/4 network |                        
 +----+       |              |   +---------------+   |                |
              +--------------+                       +----------------+  		                                                          		                                         		                         		                                   
		                                                                      	    		
			      	

Figure 2. IPv4/IPv6 translation network for IPv4/IPv6 transition

It is difficult for the current network management system to get IPv4 and IPv6 network topology and routing information simultaneously. With I2RS, it can provide a flexible way to get both IPv4 and IPv6 network topology and other information, hence it could be very useful for trouble shooting and network management.

3.3. Requirement for I2RS from the use case

From the above use case, the requirements for I2RS are: 1. I2RS interface should support both IPv4 and IPv6. It should be able to read both IPv4 and IPv6 routing information in a timely manner. 2. I2RS interface should have enough security mechanism to protect the data that read from the routing information base. 3. I2RS interface should have data consistent protection mechanism to protect the data in the routing information base. 4. I2RS interface should allow injection of routing polices to the routing forwarding table.

4. Security Considerations

Routing information is very critical and sensitive information for the operators. I2RS should provide strong security mechanism to protect the routing information that it could not be accessed by the un-authorised users. It should also protect the security and integrity protection of the routing data.

5. IANA Considerations

No IANA action is required.

6. Acknowledgments

TBD

7. References

7.1. Normative References

[RFC2119] Bradner, S., "Key words for use in RFCs to Indicate Requirement Levels", BCP 14, RFC 2119, March 1997.

7.2. Informative References

[RFC4271] Rekhter, Y., Li, T. and S. Hares, "A Border Gateway Protocol 4 (BGP-4)", RFC 4271, January 2006.
[RFC4213] Nordmark, E. and R. Gilligan, "Basic Transition Mechanisms for IPv6 Hosts and Routers", RFC 4213, October 2005.
[RFC6146] Bagnulo, M., Matthews, P. and I. van Beijnum, "Stateful NAT64: Network Address and Protocol Translation from IPv6 Clients to IPv4 Servers", RFC 6146, April 2011.
[I-D.atlas-irs-ps] Atlas, A., "Interface to the Routing System Problem Statement", Internet-Draft draft-atlas-i2rs-problem-statement-01, February 2013.

Author's Address

Dapeng Liu China Mobile Unit2, 28 Xuanwumenxi Ave,Xuanwu District Beijing 100053, China EMail: liudapeng@chinamobile.com