Bad internet connection between Mac pro and home router (Wifi and Ethernet)

The 2012 model were sold with a new feature -- 802.11n 450. That means they were capable of going up to 450 M Bits/sec under ideal conditions using three antennas with 802.11n.

Hold down the Option key while you click on the Wi-Fi Icon on the menubar. You get a snapshot like this older one:

Screen shot or transcribe the value in the snapshot, and answer:

"How many Networks do you see?"

<<Is it possible the Airport Extreme card has some issue?>>

Your Wi-Fi card may have its antennas disconnected, or the card may have essentially failed. Right next to the Router should give you an RSSI near -50 or Higher, i.e., closer to zero).

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Unless your cables are mis-wired, it is nearly impossible to be getting similar awful results over Ethernet. Use Network Utility, which should be in:

/Applications/Utilities ...

... to examine the Ethernet interface. Its report should resemble this one:

.

Your Mac sends packets intended for the Internet through the TopMost, Working interface shown in

System Preferences > Network

To use Ethernet, it must be the topmost interface, or Wi-Fi must be turned OFF -- otherwise you are likely still using Wi-Fi.

Your Router is using Channel 11on the very busy and interference-prone 2.4GHz band.

You do not have a lot of competition showing here, but your signal strength is -78 dB, and noise is at -85, leaving a signal-to-noise of only 7 dB, which is horrible. You are lucky to be getting a connection at all.

If you were right on top of the Router, you would expect to see RSSI between -50 and -10, and speeds of 300 or higher if there were no interference from other networks.

If you wish to continue to use Wi-Fi, you will need to re-configure your Network, possibly decreasing the distance between the nearest Router and your Mac Pro.

I made a mistake in my comment above about the capabilities of the 2012 MacBook Pro having 802.11n at 450. In re-reading, I see that yours is a Mac Pro 2012, which should have similar capabilities. I regret the error.

If you have Ethernet, you should use Ethernet. 100 M bits/sec should be easy to attain in almost any setup. With correctly-wired 8-conductor cables, you may be able to reach Gigabit speeds if your Router supports it.

What is shown for the connection SPEED? that is an actual measurement of the data rate you are using, where the thing in System preferences > Networks is what you have requested.

The number of packets does not matter, as long as it is "many". It just goes up with continued use, and is reset by a Restart.