单项选择题
A. Martini based VPNs
B. 2547bis based VPNs
C. Sham link based VPNs
D. Virtual Router based VPNs
单项选择题 Which statement would prevent the sending of redundant route advertisements when your routereflector cluster is fully meshed?（）
多项选择题 Which two statements are true by default of a multilevel IS-IS network?（）
单项选择题 In IS-IS, how long will the restart helper keep the restarting router in the up state?（）