In the configuration in OSPF，There are portions of the content certification，OSPF authentication is divided into two，They are
- Based authentication area
- Based authentication link (port)
The same time，Authentication mode can also be divided into two，One is plain text authentication，Another is the MD5 encrypted authentication。
Here we do not discuss OSPF encryption method，It is simply illustrative ofRegional links and similarities and differences between these two types of authentication。[……]