OSPFv2 与 OSPFv3 的比较

OSPFv2代表开放最短路径优先版本 2 ， OSPFv3代表开放最短路径优先版本3。OSPFv2 是 IPv4 的 OSPF 版本，而 OSPFv3 是 IPv6 的 OSPF 版本。在 OSPFv2 中，每个接口不支持多个 OSPF 实例，而在 OSPFv3 中，每个接口支持多个 OSPF 实例。

OSPFv3 和 OSPFv2 之间几乎没有相似之处，它们是：

1. 数据包类型
2. 接口类型
3. 邻居发现模式
4. LSA 泛洪和老化

除了这些相似之处外，还有一些不同之处如下：

S.NO	OSPFv2	OSPFv3
1.	OSPFv2 is the IPv4’s OSPF version.	While OSPFv3 is the IPv6’s OSPF version.
2.	The header size of OSPFv2 is 24 bytes.	While the header size of OSPFv2 is 16 bytes.
3.	OSPFv2 have seven link-state advertisement.	OSPFv3 have nine link-state advertisement.
4.	There is only one instance per link, in OSPFv2.	While there are many instances per link, in OSPFv3.
5.	In OSPFv2, many OSPF instances per interface are not supported.	Whereas in OSPFv3, many OSPF instances per interface are supported.
6.	There is no flooding space in OSPFV2.	While there is present flooding space in OSPFv3.
7.	OSPFv2 runs on subnets rather than links.	While OSPFv3 runs on links rather than subnets.
8.	Need network mask for adjacency formation.	Doesn’t need network mask for adjacency formation.
9.	MD5 Hashing is used for Authentication.	IPSec is used for Authentication.
10.	Nodes from different subnets can’t communicate.	Nodes from different subnets can communicate.