draft-jeong-hmipv6-dns-optimization-00.txt

bind-3.2.

                   
                   
               5. Neighbor Discovery extension - RDNSS option message format 
                   
                  The mechanism of this document needs a new option in Neighbor 
                  Discovery [7]. 
                   
                    0                   1                   2                   3  
                    0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1  
                    +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 
                    |     Type      |  Length( = 3) |  Pref |       Reserved        | 
                    +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 
                    |                           Reserved                            | 
                    +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 
                    |                                                               | 
                    +                                                               + 
                    |                                                               | 
                    +                     IPv6 Address for RDNSS                    + 
                    |                                                               | 
                    +                                                               + 
                    |                                                               | 
                    +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 
                   
                   
                
                
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                    Fields:  
                   
                      Type            Message type. TBA.  
                   
                      Length          8-bit unsigned integer. The length of the 
                                      option (including the type and length fields) 
                                      in units of 8 octets.  The default value is 3. 
                                      The value 0 is invalid. Nodes MUST silently 
                                      discard an ND packet that contains an option with 
                                      length zero. 
                   
                      Pref            The preference of an RDNSS. A 4 bit unsigned 
                                      integer. A decimal value of 15 indicates the 
                                      highest preference. A decimal value of 0 
                                      indicates that the RDNSS can not be used. 
                   
                      IPv6 Address for RDNSS 
                                      The RDNSS IPv6 address. The scope of the address 
                                      can be any scope. 
                                      i.e., link-local, site-local and global. 
                                      The prefix of the address is be /64. 
                   
                  When advertising more than one RDNSS, as many RDNSS options as the 
                  number of RDNSSs are included in an RA message. 
                   
               6. RDNSS selection by the Mobile Node 
                   
                  When a mobile node perceives multiple RDNSSs through RA message, it 
                  stores the RDNSSs in order into the configuration the resolver on the 
                  node uses for DNS name resolution on the basis of the value of "Pref" 
                  field and the prefix of "IPv6 Address for RDNSS" field in the RDNSS 
                  option. The following algorithm is simply based on the rule of 
                  selecting the nearest possible RDNSS, providing that its preference 
                  value did not reach the maximum value of 15. When the distances are 
                  the same, this algorithm uses the preference value to order the 
                  RDNSSs. The mobile node operation is shown below: 
                   
                  1) Receive and parse all RDNSS options 
                   
                  2) Arrange RDNSSs in an ascending order, starting with the nearest 
                     RDNSS and store them in the configuration for DNS name resolution 
                     used by resolver. (i.e., the longest prefix matching between the 
                     "IPv6 Address for RDNSS" field and mobile node's On-link CoA 
                     (LCoA) MAY be used to decide the distance between mobile node and 
                     RDNSS, how far away the mobile node is from the RDNSS.) 
                      
                  3) For each RDNSS entry, check the following; 
                     - If the value of "Pref" field is set to zero, exclude the RDNSS 
                       entry from the list of RDNSSs of the configuration for DNS name 
                
                
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                       resolution. 
                   
                  Whenever the resolver on the mobile node performs the name resolution, 
                  it refers to the address(es) of RDNSS in the configuration for name 
                  resolution according to the current rule of selecting an RDNSS, 
                  namely from the 1st RDNSS. 
                   
               7. Detection of RDNSS failure 
                   
                  A MAP placed in a MAP domain checks periodically if the RDNSSs 
                  registered in the MAP are alive. Whenever the MAP detects the failure 
                  of any RDNSS, it advertises the failure down to the hierarchy with a 
                  new RA message including an RDNSS option of which "Pref" field has 
                  zero for the RDNSS. When a mobile node receives the RA message, it 
                  perceives that the RDNSS is out of work or the path to the RDNSS is 
                  broken and excludes the RDNSS from the configuration for name 
                  resolution. 
                   
                  The dynamic detection of RDNSS failure in a MAP can be done by simply 
                  pinging the RDNSS periodically (e.g., every ten seconds). If no 
                  response is received, the MAP MAY try to aggressively ping the RDNSS 
                  for a short period of time (e.g., once every 5 seconds for 15 
                  seconds); if no response is received, an RDNSS option MAY be sent 
                  with a preference value of zero. 
                   
               8. Security Considerations 
                   
                  In order to guarantee the secure communication between routers, the 
                  router advertisements sent between routers SHOULD be authenticated by 
                  AH or ESP [3]. This security is essentially related to Neighbor 
                  Discovery protocol security [7]. 
                   
               9. References 
                
                  [1] Bradner, S., "The Internet Standards Process -- Revision 3", BCP 
                       9, RFC 2026, October 1996. 
                   
                  [2] Bradner, S., "Key words for use in RFCs to Indicate Requirement 
                       Levels", BCP 14, RFC 2119, March 1997 
                   
                  [3] H. Soliman, C. Castelluccia, K. El-Malki and L. Bellier, 
                       "Hierarchical Mobile IPv6 mobility management (HMIPv6)", draft-
                       ietf-mobileip-hmipv6-07.txt, October 2002. 
                   
                  [4] S. Thomson and T. Narten, "IPv6 Stateless Address 
                       Autoconfiguration", RFC2462. 
                   


                
                
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                  [5] A. Durand, J. itojun and D. Thaler, "Well known site local 
                       unicast addresses to communicate with recursive DNS servers", 
                       draft-ietf-ipv6-dns-discovery-07.txt, October 25 2002. 
                   
                  [6] Luc Beloeil, "IPv6 Router Advertisement DNS resolver Option", 
                       draft-beloeil-ipv6-dns-resolver-option-01.txt, January 2003. 
                   
                  [7] T. Narten, E. Nordmark and W. Simpson, "Neighbour Discovery for 
                       IP version 6", RFC 2461. 
                   
               10. Author's Addresses 
                   
                  Jae-Hoon Jeong 
                  ETRI / PEC 
                  161 Gajong-Dong, Yusong-Gu 
                  Daejon 305-350 
                  Korea 
                   
                  Phone: [phone] 
                  EMail: [e-mail] 
                   
                  Jung-Soo Park 
                  ETRI / PEC 
                  161 Gajong-Dong, Yusong-Gu 
                  Daejon 305-350 
                  Korea 
                   
                  Phone: [phone] 
                  EMail: [e-mail] 
                   
                  Kyeong-Jin Lee 
                  ETRI / PEC 
                  161 Gajong-Dong, Yusong-Gu 
                  Daejon 305-350 
                  Korea 
                   
                  Phone: [phone] 
                  EMail: [e-mail] 
                   
                  Hyoung-Jun Kim 
                  ETRI / PEC 
                  161 Gajong-Dong, Yusong-Gu 
                  Daejon 305-350 
                  Korea 
                   
                  Phone: [phone] 
                  EMail: [e-mail] 
                

                
                
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