Question Network running of 100 Mbps instead of 1 Gbps

Dark Sorrow

Feb 17, 2016
I've a TP Link AC1200 Wireless MU-MIMO Gigabit Router as a primary router where firewall is enforced and all my PCs are connected to the TP Link AC1200 Gigabit Router via a Dlink 8-Port Unmanaged Gigabit Switch.
My TP Link AC1200 Gigabit Router is connected to ISP supplied FTTH router which is also a Gigabit Router.
All my cabling is done using D Link CAT6 cable and all the PC (7 nos.) are based on GA-A320M-S2H (rev. 1.x) using Ryzen 3200G running Windows 10 Professional (6 nos.) or CentOS (1 nos).

Even though all my network components are Gigabit Ethernet capable however I'm only getting 100 Mbps speed. What could have gone wrong?

I plan to install Qnap TS-451+ NAS in immediate future which will house data from all PCs and will also backup data on cloud. For this reason I would prefer that my network is Gigabit Ethernet enabled.
You need to look and see what ports are running at 10/100 rather than gigabit. In is in the status field on your ethernet port. You need to be sure that the setting in the nic are AUTO. The switch might also have a different light pattern/color depending on what the port speed is. you will need to read the manual to see.

This has to be a cable issue. I did not know dlink makes cables. The only ones I found when I searched where flat cables on amazon. I suspect these are not actually dlink cables and they are fake ethernet cables also. If dlink actually does make ethernet cables the cable must be pure copper with wire size 22-24. Those flat cables have wires that are way too thin and they cause problems like you describe.


Jan 27, 2011
Modern ethernet cables have 4 pairs of wires and 100mbs only uses 2 pairs, while gigabit uses 4 pairs.

I would check your cable ends, did you crimp them yourself? I suspect 1 of the pairs is not making contact, so your system reverted to using 2 pairs.