一道网工面试题

shajia

面试遇到一道题， 主机B 的掩码不小心被配错了， 问A 和B 能通信吗？为什么？

Orange农夫

模拟测试了一下，不能，a和b不在同一sbunet，a或者b和router不在同一subnet

scoopy

我觉得如果2个设备如果都能联通 192.168.26.2 的网关的话，从右到左应该没问题吧？

如果在左边的设备上设arp table，从左到右应该也能通。

seaflash2000

不是网工，但根据经验是不能通信的。 子网掩码错啦，确定不了子网，就谈不上定位主机啦。 感觉通信过程是 1）用掩码找子网 2）用IP定主机。 非专业的， 错啦请包涵。

太和里8号

如果用switch,不能，直连用CROSSOVER，有可能。

epoxboy

depends where they are:
1, both are connected to a layer 2 switch, then they can, because on layer2 they use broadcast for communication(MAC address)

2, if they are using NAT and connected to different routers for the communication, they can.

3, if one of them or both are connected to one layer3 switch or router,  then they can NOT communicate with each other because first subnet already include second subnet IP address, you can't deploy them on same router.