Packet Loss On Switch Port OpenWRT

Hi i'm using a BT Home Hub 5A running OpenWrt 19.07.3. Specs below.

Hostname OpenWrt
Model BT Home Hub 5A
Architecture xRX200 rev 1.2
Firmware Version OpenWrt 19.07.3 r11063-85e04e9f46 / LuCI openwrt-19.07 branch git-20.136.49537-fb2f363

Basically my network is setup with scenario 1 with the 2 pair cable (is wired with two pairs that are in the walls of my house).

Scenario 1 i have packet loss.

Scenario 2 i don't have any.

Seems by adding another device in between before it runs up to my other 1Gbps switch it removes the packet loss.

Since cabling is only capable of 100Mbps i thought it may be something to do with auto negotiation but looks like port is correctly negotiating at 100Mbps. Any ideas? I'm guessing it's a setting QoS or something like that.

Gigabit Ethernet hardware on both ends of two pair cable does not meet any standards-- the operation will be unpredictable. If you have two pair cable there needs to be a 10/100 device on one end to ensure it falls back to operate at 100.

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Sorry forgot to add the image of the Scenario's. Have just added. Could i force set the port at 100Mbps to ensure it doesn't try to auto-negotiate at 1000Mbps?

Using ping -A i'm seeing a jerky pinging that results in around 2% packet loss.

Port 1 is Negating properly though.

Port 1:
uvr: 0
vsr: 0
vinr: 0
tvm: 0
pvid: 1
link: port:1 link:up speed:100baseT full-duplex auto

Which category is your two pair cable, and how long is it? Note that autonegotiation does not measure the cable quality.

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On the chipsets that I know, OpenWrt's swconfig doesn't support changing the speed, but you could try on your other switch.

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Ah right. That's a bit annoying. Other switch? It's un-managed unfortunately. But that probably explains why adding in a unmanaged 100Mbps switch fixes the issues.

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You could run swconfig help to see if there are any speed-related options for the XRX200.

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Doesn't look like it, unless it would be a 'Activate hardware change'?

root@OpenWrt:~# swconfig dev switch0 help
switch0: eth0(Lantiq XRX200 Switch), ports: 7 (cpu @ 6), vlans: 64
        Attribute 1 (int): enable_vlan (Enable VLAN mode)
        Attribute 2 (none): apply (Activate changes in the hardware)
        Attribute 3 (none): reset (Reset the switch)
        Attribute 1 (int): vid (VLAN ID (0-4094))
        Attribute 2 (int): enable (Enable VLAN)
        Attribute 3 (ports): ports (VLAN port mapping)
        Attribute 1 (int): uvr (Unknown VLAN Rule)
        Attribute 2 (int): vsr (VLAN Security Rule)
        Attribute 3 (int): vinr (VLAN Ingress Tag Rule)
        Attribute 4 (int): tvm (Transparent VLAN Mode)
        Attribute 5 (int): pvid (Primary VLAN ID)
        Attribute 6 (unknown): link (Get port link information)