单选题What is the purpose of IS-IS level boundaries?（）A Restrain the formation of adjacencies.B Control the flooding scope of link-state PDUs.C Partition the L2 backbone into multiple domains.D Aggregate L1 domains into a contiguous backbone.
题目
单选题
What is the purpose of IS-IS level boundaries?（）
A
Restrain the formation of adjacencies.
B
Control the flooding scope of link-state PDUs.
C
Partition the L2 backbone into multiple domains.
D
Aggregate L1 domains into a contiguous backbone.