【单选题】
设M=P1r1…Psrs，其中P1，P2…需要满足的条件是什么？（）
A、两两不等的合数
B、两两不等的奇数
C、两两不等的素数
D、两两不等的偶数
查看正确答案
A、A. P1R1 is the exi t point out of the area for P1R3. B、B. P1R1 is a level - 1 only IS - IS router. C、C. P1R1 has been configured with a nondefault IS - IS metric. D、D. P1R3 is a level - 2 only IS - IS router. E、E. P1R3has been configured with a nondefault IS - IS metric. F、F. P1R3 routing ta ble should contain i L2 entries.
