There are different routing protocols available for IPv6 because routing for IPv6 is needed just as it is for IPv4.
IPv6 也需要路由，因此有多種可用於 IPv6 的路由協定。
The same rules apply for routers using IPv6 as they do for IPv4. Routers can learn where to forward packets to destination networks that are not directly connected by performing static or dynamic routing. Because static routing is best suited for small networks where changes rarely happen, dynamic routing is recommended in medium or large networks.
使用 IPv6 的路由器所適用的規則與 IPv4 相同。路由器可以透過靜態或動態路由，得知如何將封包轉送至非直接連接的目的地網路。由於靜態路由最適合變動很少的小型網路，因此在中大型網路中建議使用動態路由。
To support IPv6, all the IPv4 routing protocols had to go through varying degrees of changes, with the most obvious being that each had to be changed to support longer addresses and prefixes.
為了支援 IPv6，所有 IPv4 路由協定都必須經歷不同程度的變動，其中最明顯的是每種協定都必須修改以支援較長的位址與前綴。
As with IPv4, most IPv6 routing protocols are IGPs, with BGP still being the only EGP of note. All these IGPs and BGP were updated to support IPv6. The table lists the routing protocols and their new Request for Comments (RFC)s.
與 IPv4 相同，大多數 IPv6 路由協定都屬於 IGP，而 BGP 仍是唯一值得一提的 EGP。這些 IGP 以及 BGP 都已更新以支援 IPv6。下表列出這些路由協定及其新的 Request for Comments（RFC）。
Each of these routing protocols had to be changed to support IPv6. The actual messages that are used to send and receive routing information have changed, using IPv6 headers instead of IPv4 headers and using IPv6 addresses in those headers. For example, RIP next generation (RIPng) sends routing updates to the IPv6 destination multicast address ff02::9 instead of to the former RIPv2 IPv4 224.0.0.9 address. Also, the routing protocols typically advertise their link-local IPv6 address as the next hop in a route.
每一種路由協定都必須經過修改才能支援 IPv6。用來傳送與接收路由資訊的實際訊息已經改變，改用 IPv6 標頭而非 IPv4 標頭，並在標頭中使用 IPv6 位址。舉例來說，RIP next generation（RIPng）會將路由更新傳送至 IPv6 目的地群播位址 ff02::9，而不是先前 RIPv2 所使用的 IPv4 位址 224.0.0.9。此外，路由協定通常會宣告其鏈路本地 IPv6 位址作為路由中的下一跳。
The routing protocols still retain many of the same internal features. For example, RIPng is based on RIPv2 and is still a distance vector protocol, with the hop count as the metric and 15 hops as the highest valid hop count (16 is infinity). OSPF version 3 (OSPFv3), which was created specifically to support IPv6 (and also supports IPv4), is still a link-state protocol, with the cost as the metric but with many internals, including LSA types, changed. OSPFv3 uses multicast addresses, including the all OSPF routers IPv6 address ff02::5, and the OSPF DR IPv6 address ff02::6. As a result, OSPFv2 is not compatible with OSPFv3. However, the core operational concepts remain the same.
這些路由協定仍保留許多相同的內部特性。舉例來說，RIPng 是以 RIPv2 為基礎，仍是一種距離向量協定，以躍點數作為度量值，最高有效躍點數為 15（16 代表無限大）。OSPF version 3（OSPFv3）是專為支援 IPv6 而建立的（同時也支援 IPv4），它仍是一種鏈路狀態協定，以成本作為度量值，但許多內部機制（包括 LSA 類型）都已改變。OSPFv3 使用群播位址，包括所有 OSPF 路由器的 IPv6 位址 ff02::5，以及 OSPF DR 的 IPv6 位址 ff02::6。因此，OSPFv2 與 OSPFv3 並不相容。不過，核心運作概念仍然相同。
Dual Stack Topology
雙堆疊拓樸
A topology where IPv4 and IPv6 coexist on the end devices and the network devices is called Dual Stack. This means that both IP protocols run on the devices and it is possible to provide connectivity with IPv4 and IPv6 simultaneously. The IPv4 routing information is carried by an IPv4 routing protocol, such as OSPFv2, and the IPv6 routing information is carried by an IPv6 routing protocol, such as OSPFv3. This means that the network engineer must configure two different routing protocols for two different Layer 3 protocols and each router will have two different neighbors, one OSPFv3 IPv6 neighbor and one OSPFv2 IPv4 neighbor.
IPv4 與 IPv6 在終端裝置及網路裝置上並存的拓樸稱為雙堆疊（Dual Stack）。這表示裝置上同時執行兩種 IP 協定，能夠同時提供 IPv4 與 IPv6 連線。IPv4 路由資訊由 IPv4 路由協定（例如 OSPFv2）承載，而 IPv6 路由資訊則由 IPv6 路由協定（例如 OSPFv3）承載。這表示網路工程師必須為兩種不同的第 3 層協定設定兩種不同的路由協定，而且每台路由器都會有兩種不同的鄰居：一個 OSPFv3 IPv6 鄰居和一個 OSPFv2 IPv4 鄰居。
OSPFv3 allows you to configure one IPv6 routing protocol (OSPFv3) to carry the IPv4 and IPv6 information, thanks to the address family concept. When implementing OSPFv3, it is possible to have an IPv6 routing protocol to carry both the IPv4 and IPv6 routing information.. It is possible to configure two address families: the IPv4 address family and the IPv6 address family. This way, the network engineer configures only one routing protocol. There is one OSPFv3 IPv6 neighborship between two dual stack routers involved, and two address families are configured to carry the information for each IP protocol: IPv4 and IPv6.
透過位址家族（address family）的概念，OSPFv3 讓您可以設定單一 IPv6 路由協定（OSPFv3）來同時承載 IPv4 與 IPv6 資訊。在實作 OSPFv3 時，可以讓一種 IPv6 路由協定同時承載 IPv4 與 IPv6 路由資訊。您可以設定兩種位址家族：IPv4 位址家族與 IPv6 位址家族。如此一來，網路工程師只需設定一種路由協定。兩台涉及的雙堆疊路由器之間只會有一個 OSPFv3 IPv6 鄰居關係，並會設定兩種位址家族，分別承載 IPv4 與 IPv6 這兩種 IP 協定的資訊。