Internet DRAFT - draft-ma-v6ops-terminal-test

draft-ma-v6ops-terminal-test






Internet Engineering Task Force                                    Q. Ma
Internet-Draft                                                     L. Li
Intended status: Informational                                   T. Yang
Expires: January 17, 2013                                   China Mobile
                                                           July 16, 2012


              Terminal Test of IPv6 support and DNS Query
                    draft-ma-v6ops-terminal-test-01

Abstract

   This document introduces the terminal test under the WLAN environment
   .The test includes the ability for terminal to obtain IPv6 address,
   the sequence of DNS records query and termina behaviors in the
   condition of DNS records abnormal, for example DNS records are
   incorrect or absent.  Several personal computers and smart phones
   with different operational system have been tested.  The test results
   have been discussed and to share with internet community.

Status of this Memo

   This Internet-Draft is submitted to IETF in full conformance with the
   provisions of BCP 78 and BCP 79.

   Internet-Drafts are working documents of the Internet Engineering
   Task Force (IETF).  Note that other groups may also distribute
   working documents as Internet-Drafts.  The list of current Internet-
   Drafts is at http://datatracker.ietf.org/drafts/current/.

   Internet-Drafts are draft documents valid for a maximum of six months
   and may be updated, replaced, or obsoleted by other documents at any
   time.  It is inappropriate to use Internet-Drafts as reference
   material or to cite them other than as "work in progress."

   This Internet-Draft will expire on January 17, 2013.

Copyright Notice

   Copyright (c) 2012 IETF Trust and the persons identified as the
   document authors.  All rights reserved.

   This document is subject to BCP 78 and the IETF Trust's Legal
   Provisions Relating to IETF Documents
   (http://trustee.ietf.org/license-info) in effect on the date of
   publication of this document.  Please review these documents
   carefully, as they describe your rights and restrictions with respect
   to this document.  Code Components extracted from this document must



Ma, et al.              Expires January 17, 2013                [Page 1]

Internet-Draft                 TEST-RESULT                     July 2012


   include Simplified BSD License text as described in Section 4.e of
   the Trust Legal Provisions and are provided without warranty as
   described in the Simplified BSD License.


Table of Contents

   1.  Introduction  . . . . . . . . . . . . . . . . . . . . . . . . . 3
   2.  Terminal test . . . . . . . . . . . . . . . . . . . . . . . . . 3
     2.1.  Test topology and process . . . . . . . . . . . . . . . . . 3
     2.2.  test cases  . . . . . . . . . . . . . . . . . . . . . . . . 4
     2.3.  Test results and analysis . . . . . . . . . . . . . . . . . 5
   3.  Conclusion  . . . . . . . . . . . . . . . . . . . . . . . . . . 5
   4.  Security Considerations . . . . . . . . . . . . . . . . . . . . 6
   5.  IANA Considerations . . . . . . . . . . . . . . . . . . . . . . 6
   6.  Acknowledgement . . . . . . . . . . . . . . . . . . . . . . . . 6
   Authors' Addresses  . . . . . . . . . . . . . . . . . . . . . . . . 6


































Ma, et al.              Expires January 17, 2013                [Page 2]

Internet-Draft                 TEST-RESULT                     July 2012


1.  Introduction

   With fast development of global Internet, the demands for IP address
   are rapidly increasing at present.  IANA announced that the global
   free pool of IPv4 depleted on February 3, 2011.  IPv6 is only way to
   satisfy demands of internet development.  Operators have to
   accelerate the process of deploying IPv6 networks in order to address
   IP address strains.

   DNS server provides name resolution and resource location services.
   Domain Name Service translates queries for domain names (which are
   meaningful to humans) into IP addresses for the purpose of locating
   computer services and devices worldwide.  Until IPv6 completely
   supplants IPv4, most internet applications implement IPv4 and IPv6
   protocol stacks either independently or in a hybrid form.  In order
   to establish transition strategy, China Mobile processed some tests
   to make it clear that the behaviors of DNS server and terminal in a
   dual stack ( IPv4 [RFC0791]+IPv6 [RFC2460] ) deployment and IPv6 only
   deployment under the WLAN environment.

   This document has described detailed testing topology, cases and
   process.  The testing results have been summarized and analyzed to
   provide explicit conclusions for further deployment.


2.  Terminal test

2.1.  Test topology and process



   +--------------+     +--------+     +-------+     +-------------+
   |PC/smart phone|-----|   AP   |-----|   AC  |-----|DNS Server   |
   +--------------+     +--------+     +-------+  |  +-------------+
                                                  |
                                                  |  +-------------+
                                                  +--|Web Server   |
                                                     +-------------+


                          Figure 1: Test topology

   Figure 1 shows the configuration of terminal test environment.  The
   terminals include personal computer and smartphone, As an access
   point, AP provided WLAN access environment.  As an access controller
   and DHCP server, AC assigned a terminal IP address and other
   configuration information.  The resource records in the DNS server
   were deployed to some different conditions.



Ma, et al.              Expires January 17, 2013                [Page 3]

Internet-Draft                 TEST-RESULT                     July 2012


   The tester make the terminal connected to AP, then input a domain
   name in the terminal browser and try to visit the corresponding Web
   page.  The traffic flow between terminal and DNS/WEB server was
   captured by packet analyzer.  For PC terminal, message flow is
   captured by a wireshark software in the PC.  For smartphone terminal,
   the message flow is captured from air interface.  The massage flow is
   analyzed and the results were summarized.

2.2.  test cases

   1.The ability for terminal to obtain IPv6 address

   The DHCP server was set to assign the terminal IPv6 address using
   stateless address autoconfiguration or DHCPv6, respectively.  By
   analyzing the packet to determine whether The terminals were able to
   obtain IPv6 address and configuration information.

   2.The behavior of DNS record query sequence

   We tested terminal in three network scenarios in our labotory.

   1)Terminals and DNS server all have dual stack (IPv4+IPv6) address;

   2)terminals have dual stack (IPv4+IPv6) address and DNS server has
   only IPv6 address;

   3)Terminals and DNS server all have only IPv6 address;

   There were four deployments of resource record corresponding to a
   domain name in the DNS server: both A and AAAA record; only AAAA
   record, nonexistent DNS record and error condition.  The error
   condition include: A record incorrect, AAAA record incorrect and both
   incorrect.  Table 1 shows the deployments of DNS records.

 TABLE 1. Different deployments of DNS records

 Domain name    DNS record condition    IP address
 -----------------------------------------------------------------------
 www.a.com      both A and AAAA         10.10.100.2/2002:200:200::2
 www.b.com      only AAAA               2002:200:200::2
 www.c.com      A incorrect             10.10.100.100/2002:200:200::2
 www.d.com      AAAA incorrect          10.10.100.2/2002:200:200::200
 www.e.com      both incorrect          10.10.100.100/2002:200:200::200



   In above cases, terminal was connected to WLAN network and tried to
   set up a TCP connection to visit a web page.  The process of message



Ma, et al.              Expires January 17, 2013                [Page 4]

Internet-Draft                 TEST-RESULT                     July 2012


   interactive between terminal and DNS/WEB server was captured and
   analyzed.

2.3.  Test results and analysis

   (1)The IPv6 support in the operating systems is not perfect.  Some
   operating sysytems are not able to obtain IPv6 address and DNS using
   DHCPv6.

   (2) The sequence of DNS query depends on the operating system of
   terminal.In the case of dual stack, termianls will look up A and AAAA
   record in turn.  Some terminals look up the DNS record using IPv6
   address firstly, while others using IPv4 address firstly.

   (3) Certain operating systems have naive algorithm.  In the case of
   assigned only IPv6 address, the terminal requests an A type record
   firstly.  It is unnecessary for a terminal with only IPv6 address to
   look up an A type record.

   (4) Certain terminals carry unnecessary DNS queries.  When there is
   only AAAA record in the DNS sever and terminal have dual stack
   addresses, certain operating system will look up an A record
   corresponding to a domain name several times after getting AAAA
   record, even after having visited the web page with AAAA record
   successfully.  For a non-existent domain name, most terminals prefer
   to query all DNS records including A and AAAA, though they have
   received the "no such name" reply corresponding to the first query.

   (5) When obtaining both A and AAAA record , certain of terminals
   prefer using AAAA record to visit the web site.  If terminals fail to
   set up a TCP connection using AAAA record due to incorrect AAAA
   record, it will retry two times with AAAA record, and then turn to
   use the A record.

   (6)Without IPv4 address, some operating sysytems can not visit the
   web page properly with only IPv6 address, and of course all the
   tested teminals can work with only IPv4 address without IPv6 address.

   (7)The happy eyeballs (RFC6555) mechanism is used to improve the
   dual-stack users experience.  Amony all the tested operating
   sysytems, the happy eyeballs mechanism is not observed.


3.   Conclusion

   The test results show that the IPv6 support in the operational
   systems are not perfect.  There are many unnecessary DNS queries and
   traffic flows.  It has the potential to cause a DNS server and



Ma, et al.              Expires January 17, 2013                [Page 5]

Internet-Draft                 TEST-RESULT                     July 2012


   network overloaded.  In the development of transition strategy form
   IPv4 to IPv6, the test results will be taken into account and pay
   more attention.


4.  Security Considerations

   It needs to be further identified.


5.  IANA Considerations

   TBD


6.  Acknowledgement

   Thanks for the contributions from Fan Peng.


Authors' Addresses

   Ma Qiongfang
   China Mobile
   32, Xuanwumenxi Ave.
   Xicheng District, Beijing  01719
   China

   Email: maqiongfang@chinamobile.com


   Li Lianyuan
   China Mobile
   32,  Xuanwumenxi Ave.
   Xicheng District, Beijing  01719
   China

   Email: lilianyuan@chinamobile.com


   Yang Tianle
   China Mobile
   32, Xuanwumenxi Ave.
   Xicheng District, Beijing  01719
   China

   Email: yangtianle@chinamobile.com




Ma, et al.              Expires January 17, 2013                [Page 6]