OSPF (Open Shortest Path First) is an Interior Gateway Protocol (IGP). It is a link-state routing protocol that uses the Shortest Path First (SPF) algorithm to calculate the best route. OSPF routing protocol is an open standard, so various network vendors implement it. Here are the most important features of OSPF: A classless routing protocol

To configure OSPF, we need to enable OSPF on both routers first. Then we need to define what network will be advertised in OSPF using the following sequence of commands on both routers:

2014年5月13日 · （1）在每个 路由器 上启用OSPF，使得网络互联互通. （2）验证OSPF配置：理解OSPF邻接关系的建立、理解以太网广播型网络DR/BDR的选举. （3）理解广播多路访问链路上和点对点链路上的OSPF 特征. 3、配置过程： （1）每个路由器上按图配置好IP地址并启用回环口： Interface IP-Address OK? Method Status Protocol. Interface IP …

CCNA students need to understand how OSPF works but also how to configure it. If you have no idea what OSPF is or if you are a little fuzzy, I recommend you to read my Introduction to OSPF first before continuing.

2025年3月25日 · OSPF authentication: For more advanced setups, if OSPF authentication is enabled on one side and not the other (or passwords don't match), neighbors won't form. This likely isn't the case in a basic CCNA lab unless explicitly configured. Essential OSPF Show Commands for Verification and Troubleshooting

From foundational OSPF theory to advanced configurations, this course provides a step-by-step approach to help you learn everything you need to know about OSPF. Packed with practical labs, troubleshooting tickets, and advanced topics, you’ll gain the hands-on skills to confidently work with OSPF in real-world scenarios.

2020年4月28日 · OSPF没有使用全局的key chain，是单独配置的密钥. 明文认证既可以在接口认证也可以在全局认证，接口的话更精确点，把一个区域上所有的接口启用相同的认证和在一起区域内全局启用认证效果是一样的。 明文认证的密码可以在网络上使用抓包软件抓取。 ②启动ospf 认证. ③指定明文认证的密钥. ②开启并指定md5认证. ③指定MD5加密认证的密钥. 在生产环境除非不支持，否则优先使用MD5认证. OSPF 是 有限制的汇总， 只能在区域边界路由器ABR上进行汇 …

2025年3月16日 · This tutorial explains how to configure the OSPF routing protocol on Cisco routers. Learn how to enable and manage OSPF routing.

In part 1 of this chapter, we will review concepts on link-state routing protocols and learn how they work. We will then look at the OSPF packets and discuss the algorithm that OSPF uses to find the best part. We will then configure OSPF in a single area and finally we will learn some of the commands that can be used to verify OSPF.

OSPF is a complex link-state routing protocol. Link-state routing protocols generate routing updates only when a change occurs in the network topology. When a link changes state, the device that detected the change creates a link-state advertisement (LSA) concerning that link and sends to all neighboring devices using a special multicast address.