【文件属性】：
文件名称：子网划分-CCNA中文版PPT
文件大小：10.75MB
文件格式：PPT
更新时间：2021-04-25 17:52:46
CCNA
子网划分
Other
subnets
220.160.1.0
220.160.1.32
220.160.1.64
申请到一段C类地址220.160.1.0，将这段地址分配给网络中的主机，要求有5个子网，每个子网最少有20台主机，地址分配的步骤：
1、确定网络的主机位n，利用32-n算出网络位，然后算出子网掩码
2、根据子网掩码，确定每段IP地址的范围
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Purpose: This figure explains how to plan subnet numbers.
Emphasize: What if this were a Class B address? How many bits would we have for subnetting then? Where do you want to draw the line now?
Alternatives to review: Creating the subnet at the octet boundary is easier to work with—more host bits and more subnet bits.
Explain that the decision is really a guess on how you think your network will grow—will it have more subnets or more hosts?
RFC 1219 Mirroring: Mirroring hedges the subnetting decision by buying time. Do not use mirroring if you intend to use route summarization or variable-length subnet masking (VLSM); they are incompatible with mirroring.