Airport Extreme 6: Slow download, fast upload

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Level 1

4 points

Airport Extreme 6: Slow download, fast upload

Apple Airport Extreme 6 has slow download speed but fast upload.

Have fiber optic service with 400 mps download and upload speeds. 3 extreme 6 routers all hard wired together. Two of them are speed testing at the 400mps upload and download. One is only 100mps download and 400mps upload. I swapped out the locations of all three and the slower one is always giving the same speeds and the faster ones are working fine at all three locations. I tried resetting a couple times and firmware is up to date.

AirPort Extreme

Posted on Jul 7, 2026 5:49 PM

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Answer 1

WheelieNick

Level 9

55,481 points

Aug 11, 2026 3:35 AM in response to Kiko49

Your specific 100 Mbps download bottleneck on one AirPort Extreme—despite working fine in all locations and showing normal 400 Mbps upload—points to an Ethernet negotiation failure (running at Fast Ethernet 100 Mbps instead of Gigabit 1000 Mbps) or a failing internal switch/port on that specific unit. Because upload hits 400 Mbps, it is not a pure Wi-Fi 2.4GHz limitation, but rather a duplex or hardware constraint on the LAN/WAN interface

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