401-101的第46题求解

FireFire

Why is the neighbor relationship between R2 and R4 shown as ES-IS?
A. because there is an MTU mismatch between R2 and R4
B. because interface S3/0 of R4 is configured as L1/L2
C. because interface S3/0 of R2 is configured as L1
D. because there is a hello interval mismatch between R2 and R4

有关ISIS之间建立邻接关系的.答案说是C.因为R2的S3/0口是L1.

http://books.google.ca/books?id=acUH-XvDFKMC&pg=PA605&dq=problem+3:+only+es-is+adjacency+instead+of+IS-IS+adjacency+formed&hl=en&sa=X&ei=Piy8U4T6OY7ksASy94CoBw&ved=0CB0Q6AEwAA#v=onepage&q=problem%203%3A%20only%20es-is%20adjacency%20instead%20of%20IS-IS%20adjacency%20formed&f=false


Troubleshooting IP Routing Protocols edited by Faraz Shamim

这本书里面有个一样的例子,它解释的原因是说因为R2和R4之间的MTU mismatch.

求大人解答.谢谢