正确答案: D

255.255.254.0.

题目：Your network uses the172.12.0.0 class B address. You need to support 459 hosts per subnet, while accommodating the maximum number of subnets. Which mask would you use?

解析：解析：Explanation:Toobtain459hoststhenumberofhostbitswillbe9.Thiscansupportamaximumof510hosts.Tokeep9bitsforhostsmeansthelastbitinthe3rdoctetwillbe0.Thisgives255.255.254.0asthesubnetmask.

查看原题 点击获取本科目所有试题

举一反三的答案和解析：

[单选题]What is the purpose of the Spanning Tree Protocol (STP)?

To maintain a loop-free Layer 2 network topology

解析：解析：Explanation:

[单选题]通配符掩码和子网掩码之间的关系是（）。

两者没有什么区别

[单选题]What is the purpose of the spanning-tree algorithm in a switched LAN?

To prevent switching loops in networks with redundant switched paths.

解析：解析：Explanation:STPisusedinLANswithredundantpathsorroutestopreventloopsinalayer2switchedorbridgedLAN.IncorrectAnswers:A,B:TheprimarypurposeofSTPistopreventloops,notformonitoringormanagementofswitchesorVLANs.D.VLANsareusedtosegmentaLANintomultiplecollisiondomains,buttheSTPprocessalonedoesnotdothis.E.Routersareusedtopreventroutingloopsatlayer3oftheOSImodel.STPoperatesatlayer2.

[单选题]IP地址为：192.168.50.70，掩码为：255.255.255.248，则该IP和掩码结合划分子网时，每个子网的容量为（）

6