Getting only 85 mbs on 500/500 internet connection

Hello there,

I have now set up an Asus PN40 mini PC as Openwrt router on my network. Its connected to my ISP router. The ISP router is set to bridge mode. The PN40 router is handling DHCP. It has only one lan port so I have set up trunk connection to a TP link 8 port switch according to Van Tech corner YT tutorial. When I do speedtest through PN40 router I get only 85mbs. If I connect PC directly to ISP router I get 500/500 mbs. The port on the PN40 is 1000mbs as all my cables also support. What can be the cause for this?

Edit: I see on Luci overview tab the eth0 port reports 100M, how to change to 1000M?

What is the specific model of the TP-Link switch?

Have you tested all of the cables involved to ensure that they are all good? Even new high-spec cables can be damaged or have manufacturing defects.

Let's take a look at your configuration:

Please connect to your OpenWrt device using ssh and copy the output of the following commands and post it here using the "Preformatted text </> " button:
Remember to redact passwords, MAC addresses and any public IP addresses you may have:

ubus call system board
cat /etc/config/network
cat /etc/config/wireless
cat /etc/config/dhcp
cat /etc/config/firewall

Most likely pause frames in a pc-router or switch. Check ethtool -a

Mmmh, start by checking the cable and the ethernet ports used. Gigabit ethernet needs all 4 wire pairs of an ethernet cable, 100mbps ethernet only needs 2 wire pairs, so when a single contact goes bad, the link will fall back to 100mbps.
Also check whether the cable actually has 4 wire pairs, I once had the same problem, with the solution being a 2 wire pair cable, I had used without noticing....

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In addition to what @moeller0 said, it could be your debris or bent pins in one of the ports (PC or switch). And, we need to know what switch model you are using.

Oh man - I replaced the cable with the cable I testet to get 500/500 speed and now it works! Thanks guys althought I guess I should have found out myself first...must be a foult in the cable as its supposed to support 1000mbs, sigh...

Its a TL-SG108E switch.


Glad the cable fixed the issue!


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