本論文主要是為了作為在企業中透過使用開源方案的軟體，提供NAT64的整合服務之研究。因網路位置的不敷使用，IETF制定了新的網際網路協定，稱為IPv6。IPv6擁有128位元的位置空間，相對於目前使用的傳統IPv4協定只有32位元，其位址數量的擴增相較於傳統的IPv4，將足以滿足未來的需求。其中，當企業內部網路使用IPv6時如何使其與IPv4連線，需要一套健全的轉換機制來解決。目前已有許多種轉換的技術，如Tunneling、Dual Stack、NAT-PT等等。本論文採用NAT64、DNS64、DHCPv6等技術搭配開源軟體的使用，將其建構成為一整合方案，並透過單一主機、設備的方式實現。而本論文的成果，將可使企業在改動內部網路最小的情況下來實現。

This thesis aims to provide the way for NAT64 in the enterprise using open source solution. The shortage of traditional IPv4 address is one of the serious problems in the field of Internet nowadays. IETF has proposed the next generation Internet Protocol, named Internet Protocol Version 6 (IPv6). As the total number of possible IPv6 address is more than 7.9* 1028 times as many as IPv4. However, it is impossible when the IPv6 client wants to communicate with IPv4 client directly. It needs a solution to enable IPv6 client to communicate with IPv4 client using transition mechanism. So far a lot of transition mechanisms have been proposed, such as Tunneling, Dual Stack and NAT-PT. In this thesis, we will design and implement an NAT64 with DNS64 and DHCPv6 to achieve the goal on the open source platform.

致謝 I
目錄 IV
表目錄 VI
圖目錄 VII
第壹章 緒論 1
第貳章 IPv6現行轉換技術與IPv4之差異 3
2.1 IPv4與IPv6定址與表示方法 3
2.1.1 IPv4（Internet Protocol Version 4）3
2.2 IPv6 NAT技術 6
2.2.1雙堆疊技術（Dual Stack）6
2.2.2 穿隧技術（Tunneling）8
2.2.3 協定轉換技術（NAT-PT）11
2.2.4 IPv6動態主機設定協定（DHCPv6）15
第參章 NAT64開源系統架構與配置 19
3.1 TAYGA（NAT64）20
3.2 BIND（DNS64）21
3.3 ISC-DHCP6-SERVER（DHCPv6）22
3.4 RADVD（Router Advertisement Daemon）23
第肆章 NAT64開源系統運作與展示 25
4.1 系統架設與操作 25
4.1.1 TAYGA 25
4.1.2 BIND 27
4.1.3 ISC-DHCP-SERVER 28
4.1.4 RADVD 30
4.2 NAT64開源系統運作展示 30
第伍章 結論 36
參考文獻	37

表目錄
表2-1 IPv4位址分級 4
表2-2 IPv6位址分級 6
表2-3 IPv4/IPv6 Dual Stack優缺點	8
表2-4 Tunneling IPv6表頭位址設定	10
表2-5 Tunneling 外部IPv4 表頭位址設定 10
表2-6 IPv6 Tunneling優缺點比較 11
表2-7 NAT-PT初始封包位址格式 12
表2-8 NAT-PT IP對應表 12
表2-9 IPv6表頭轉換為IPv4表頭之位址 13
表2-10 NAT-PT優缺點比較 14
表2-11 DHCPv6訊息類型 15
表2-12 Router Advertisement封包中M、O Flag定義 17
表2-13 Router Advertisement封包中M、O Flag組合使用狀態 17

圖目錄
圖2-1 IPv4位址表示方法 4
圖2-2 IPv6位址表示方法 5
圖2-3 IPv6位址簡寫範例 6
圖2-4 Dual Stack 7
圖2-5 IPv6 tunneling 9
圖2-6 IPv6 Tunneling封包傳送過程	10
圖2-7 IPv6網路透過NAT-PT連線至IPv4網路 13
圖3-1 NAT64開源系統之架構 20
圖3-2 TAYGA運作流程 21
圖3-3 BIND運作流程 22
圖3-4 DHCPv6運作示意圖 23
圖4-1 設定TAYGA之虛擬介面IP位址 26
圖4-2 設定TAYGA所需的iptables 26
圖4-3 設定TAYGA所需的路由 26
圖4-4 設定TAYGA欲轉換用的IPv6前段與IPv4網段 27
圖4-5 啟動TAYGA	27
圖4-6 設定BIND所需的DNS Server位址與DNS64前段 28
圖4-7 設定ISC-DHCP-SERVER欲配發的IPv6位址	29
圖4-8 查看ISC-DHCP-SERVER配發狀況 29
圖4-9 設定RADVD	30
圖4-10 NAT64開源系統配置與架構 31
圖4-11 未啟動DHCPv6時之IPv6 Client位址 31
圖4-12 啟動DHCPv6、RADVD時之IPv6 Client位址 32
圖4-13 未啟動DNS64時之IPv6 Client 查詢DNS結果 32
圖4-14 啟動DNS64時之IPv6 Client查詢DNS結果 33
圖4-15 未啟動NAT64時之IPv6 Client連線結果	33
圖4-16 啟動NAT64時IPv6位址轉換為IPv4位址對應 34
圖4-17 啟動NAT64時與外部連線結果	34
圖4-18 IPv6 Client連線成功示意圖	35

[1] IDC, Mobile Internet Users to Top 2 Billion Worldwide in 2016, URL: https://www.idc.com/getdoc.jsp?containerId=prUS40855515
[2] IDC, Smartphoe OS Market Share, 2016 Q3, URL: http://www.idc.com/promo/smartphone-market-share/os
[3] Apple, Supporting IPv6-only Networks, URL: https://developer.apple.com/news/?id=05042016a
[4] Cisco, NAT64 Technology: Connecting IPv6 and IPv4 Networks, URL: http://www.cisco.com/c/en/us/products/collateral/ios-nx-os-software/enterprise-ipv6-solution/white_paper_c11-676278.html
[5] IETF, INTERNET PROTOCOL DARPA INTERNET PROGRAM PROTOCOL SPECIFICATION, URL: https://tools.ietf.org/html/rfc791
[6] IETF, Internet Protocol, Version 6 (IPv6) Specification, URL: https://tools.ietf.org/html/rfc2460
[7] IETF, Transition Mechanisms for IPv6 Hosts and Routers, URL: https://tools.ietf.org/html/rfc1933
[8] IETF, Transmission of IPv6 over IPv4 Domains without Explicit Tunnels, URL: https://www.ietf.org/rfc/rfc2529.txt
[9] IETF, Connection of IPv6 Domains via IPv4 Clouds, URL: https://www.ietf.org/rfc/rfc3056.txt
[10] IETF, IPv6 Tunnel Broker, URL: https://tools.ietf.org/html/rfc3053
[11] IETF, Intra-Site Automatic Tunnel Addressing Protocol (ISATAP), URL: https://tools.ietf.org/html/rfc5214
[12] IETF, Basic Transition Mechanisms for IPv6 Hosts and Routers, URL: https://tools.ietf.org/html/rfc4213
[13] IETF, IPv6 Rapid Deployment on IPv4 Infrastructures (6rd), URL: https://tools.ietf.org/html/rfc5569
[14] IETF, Stateless IP/ICMP Translation Algorithm (SIIT), URL: https://tools.ietf.org/html/rfc2765
[15] IETF, Network Address Translation - Protocol Translation (NAT-PT), URL: https://www.ietf.org/rfc/rfc2766.txt
[16] IETF, Dual Stack Hosts using the “Bump-In-the-Stack” Technique (BIS), URL: https://tools.ietf.org/html/rfc2767
[17] IETF, Dual Stack Hosts Using “Bump-in-the-API” (BIA), URL: https://tools.ietf.org/html/rfc3338
[18] IETF, A SOCKS-based IPv6/IPv4 Gateway Mechanism, URL: https://tools.ietf.org/html/rfc3089
[19] An IPv6-to-IPv4 Transport Relay Translator, URL: https://tools.ietf.org/html/rfc3142
[20] IETF, Dynamic Host Configuration Protocol for IPv6 (DHCPv6), URL: https://tools.ietf.org/html/rfc3315
[21] IETF, IPv6 Stateless Address Autoconfiguration, URL: https://tools.ietf.org/search/rfc4862
[22] IETF, Neighbor Discovery for IP version 6 (IPv6), URL: https://tools.ietf.org/html/rfc4861
[23] IETF, IPv6 Router Advertisement Flags Option, URL: https://tools.ietf.org/html/rfc5075
[24] TAYGA, URL: http://www.litech.org/tayga/
[25] BIND, URL: https://www.isc.org/downloads/bind/
[26] ISC DHCP, URL: https://www.isc.org/downloads/dhcp/
[27] RADVD, URL: http://www.litech.org/radvd/
[28] IETF, DNS64: DNS Extensions for Network Address Translation from IPv6 Clients to IPv4 Servers, URL: https://tools.ietf.org/html/rfc6147
[29] IETF, NAT64 - NAT46, URL: https://tools.ietf.org/html/draft-durand-ngtrans-nat64-nat46-00