I am trying to test local speed between my computer and WRT1900ACS running 19.0.7. I am not able to go past 93~95 mbps using iperf3. The "Switch" page is going the port as 100baseT Full Duplex. All of the WRT1900ACS ports are Gigabit. Windows 10 is detecting the connection as 100 mbps as well
The connections are as follow
Intel(R) 82579V Gigabit (PC Ethernet Port)
A long CAT6 Cable with an RJ45 jack on one end and a CAT6 keystone on the other.
A CAT6E cable between the keystone and the WRT1900ACS port.
I run iperf3 -s on OpenWRT and iperf3 -c XXX.XXX.XXX.XXX -t iperf3
What am I missing here? And why OpenWRT is displaying the LAN ports are 100baseT?
While there is always the possibility of interoperability issues between die different network cards involved, this would be rather unlikely (especially with common stuff like Intel vs Marvell). Cabling issues are way more likely, so I'd recommend to check that first, by doing a new test with another cable (just get a short patch cable and test it closer to each other, not that the distance (assuming <100m) would be a problem, but the connectors or cables - and I don't expect you have another long enough cable at hand).
I have tested using another CAT5E cable (10m / RJ45 plugs at both ends) and it is the same problem. I tried to force 1Gbps full duplex mode from the Intel Chipset driver, but it shows the cable as unplugged. The WRT1900ACS just blinks the Ethernet port led on and off every 3 seconds.
I tested with another 1m CAT5E cable. Same
I tested with the cable than came with the router. Same.
You could SSH into your router via terminal or command prompt on Windows using SSH root@192.168.1.1 and the install ethtool
opkg install ethtool and then run ifconfig to list all of your interfaces. You can then run ethtool on the desired interface and it may show you some extra information.
Just for the sake of testing, perhaps connect your WAN port with the port you see affected (yes, loops are bad - but we're just interested if it negotiates the correct link speed here, not to actually pass any packets through).
I have Archer VR600 running. Attaching the cable in the first post between both routers went undetected. The WRT port led didn't even go up, but when connected between the WRT and a switch or another PC, it negotiates on 100 mbps. Very weird behavior. Connecting the CAT5E 10m cable, both routers negotiated on a 1000 mbps. The same cable connected to the Gigabit Ethernet Card on the PC negotiates only on 100 mbps.
If you don't have any testing equipment, like cable tester, your only option is to try different combinations of ports and cables until you see what can be the culprit.
E.g port 1 on router and cable a towards PC. Then port 2 on router and cable a towards PC. If the problem remains, change cable. If not, then you might have a faulty port on router. If it isn't router port or cable, check the port on the PC.
Look in the plugs confirm the wire colors are in the standard order-- a DC tester won't find split pairs.
Another common problem is for the RJ-45 contact points to be unevenly set, or the plastic comb in between them distorted, so they don't make contact all the time. Or they might make contact all the time in one device but never in another one.
