It is very important that you have the correct null modem cable with you to set up the debugging environment.

为了设置调试环境，拥有正确的零调制解调器电缆是非常重要的。

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Before starting, make sure that you have connected the null modem cable between the development and target machines.

开始之前，请确保已使用零调制解调器电缆将开发计算机和目标计算机连接起来。

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A null modem cable is a serial cable that allows data to be sent between two serial ports.

零调制解调器电缆是一种允许在两个串行端口之间发送数据的串行电缆。

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Ideally, that machine would have no network connection (as it would be a prime break-in target), and be reported to via null-modem serial cable only.

CNN: Analysis: Linux security