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I have an Enterprise grade Cisco router and an HP laptop. I would like to connect to the router on the console port to conduct out-of-band management.

The console port on the router uses an RJ45 terminal. I have one on my laptop as well. My understanding is that I can not connect directly like that, but rather must use a DB9-RJ45 adapter.

This is fine, I just have to order one and wait. But I'd like to understand why that is and to ask the question "can't whatever change is being made via the hardware adapter be addresses by software?", just to improve my understanding.

Hack-R
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1 Answers1

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While using a classical RJ45 jack, the connection on your Cisco router really is a RS232 serial connections.

This means that, independently from the physical connector, your PC need to speek the same RS232 protocol. This is why do you need a DB9 (classic serial port connector) to RJ45 converter. The converter does not change the underlying protocol, rather it only provided the correct wirings for the right pins.

On the other hand, your PC's RJ45 connector is not internally connected to a serial port; rather, it is a direct extension of your network card, which speak a completely different protocol (even at the basic electrical layer).

shodanshok
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