OSPF与IS-IS的区别

1. OSPF：
之所以开发它，是因为互联网社会需要为TCP / IP协议社区发布功能强大的非专有IGP。

OSPF是域内路由协议，它基于链路状态路由技术。它引入了一些新概念，包括路由更新的身份验证，可变长度的子网掩码(VLSM)，根摘要等。

2. IS-IS：
中间系统到中间系统是一种标准化的链接状态协议，已被开发为OSI模型的最终路由协议。

IS-IS是链路状态IGP。链路状态协议的区别在于在每个参与路由器上构建完整的网络连接图所需的信息流通。然后，此地图用于计算到达目的地的最短路径。

主要用于ISP环境。

OSPF与IS-IS的区别：

S.No.	Parameter	OSPF	IS-IS
1.	Administrative Distance	110	115
2.	Standard	RFC 2328 (OSPFv2).	ISO 10589, RFC 1195.
3.	Operating OSI Layer	OSPF operates on the top of IP layer.	IS-IS operates over L2.
4.	Virtual Links Supported	Yes	No
5.	DR/BDR Election	OSPF elects a BDR and DR on broadcast networks.	IS-IS elects a single DIS on broadcast networks.
6.	IP Connectivity	OSPF Requires the IP Connectivity between the routers to share the routing information.	IS-IS doesn’t require IP connectivity between the routers as updates are sent via CLNS instead of IP.
7.	Support	OSPF supports NBMA and point to multipoint links.	IS-IS doesn’t support.
8.	Router Area	OSPF router can belong to multiple areas.	IS-IS router can belong to only one area.
9.	Area/Level Types	Backbone Area Standard Area (Non Backbone Area)	Level 1 Level 2 Level 1/2 Areas
10.	Security	Prone to attack and hence requires more security overheads for protection.	Since, IS-IS runs on level2, hence every unlikely possibility of attack.
11.	Identification	OSPF uses Router id to identify a router on network.	IS-IS uses System ID to identify a router on the network.
12.	Flexibility	Less Flexible than IS-IS.	More Flexible to use than OSPF especially in provider domain.
13.	Table Refresh	OSPF refreshes the entire routing table after 30 minutes.	IS-IS doesn’t refresh the entire SPF Table Periodically like OSPF.
14.	Related Terms	Area, Non Backbone Area, Backbone Area, ABR, ASBR, Host.	IS, Level 1, Level 2, L1/L2, Subdomain, ES.