[ 组合题 ] C4en

Suppose an ISP owns the block of addresses of the form 128.129.80.128/26.

1、 [ 单选题 ]

Suppose the block of address is a subnet. which of the following is its subnet mask?

  • A、 255.255.0.0
  • B、 255.255.255.0
  • C、 255.255.255.128
  • D、 255.255.255.192
2、 [ 填空题 ]

Suppose it wants to create four subnets from this block, with each block having the same number of IP addresses. What are the prefixes (of form a.b.c.d/x, such as 128.129.80.128/26) for the four subnets?