starting from about 2012, the built in Ethernet port was eliminated in favor of a Thunderbolt to gigabit ethernet adapter on the retina models. I thought that most older MacBook Pro's had an Ethernet port built in, but I was wrong. Immediately do #2, the zap pram as your MacBook Pro is starting up -hold down Apple/Command key, Option, P and R keys together for 3 chimes then let go and let your macbook pro start up as usual. Hold them down for a count of 20 seconds, then let go of them, and press the power button to turn on your macbook Pro. If you have a macbook pro with a non-removeable battery, shut it down, and hold down the following keys on the keyboard to reset the smc/pmu : Shift on the left hand side of the keyboard, Control, and Option/alt on the left side of the keyboard and the power button as well. i can only give you general directions as I don't know what exact model/year of MacBook Pro you have. You could try doing a reset smc/pmu and then zap pram. You can find that out by going to the large Apple icon at the top left of your screen, then go to 'About this Mac'. Could you tell us exactly what model of MacBook Pro 13' you have, please

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