Ethernet Internet Speed Stuck at 100 Mbps for Gigabit Connection [Ubuntu 20.04 & 21.10]

My internet speed on Ethernet port is hard stuck at ~100 Mbps on wifi I get more than 500 Mbps my internet runs at Gigabit and I have full bandwidth on Pop OS live, windows on the same machine and wire.

The problem is not with the wire and router but with Ubuntu 20.04 and 21.10 for certain.

I am using CAT 7 Cable

I've tried everything and even tried upgrading to 20.10 with no luck what could be the issue here

Here's my lshw -c network output

description: Ethernet interface product: RTL8111/8168/8411 PCI Express Gigabit Ethernet Controller vendor: Realtek Semiconductor Co., Ltd. physical id: 0 bus info: pci@0000:03:00.0 logical name: eno1 version: 15 serial: 38:f3:ab:60:5d:a7 size: 1Gbit/s capacity: 1Gbit/s width: 64 bits clock: 33MHz capabilities: bus_master cap_list ethernet physical tp 10bt 10bt-fd 100bt 100bt-fd 1000bt-fd autonegotiation configuration: autonegotiation=off broadcast=yes driver=r8168 driverversion=8.048.03-NAPI duplex=full ip=192.168.1.9 latency=0 link=yes multicast=yes port=twisted pair speed=1Gbit/s resources: irq:59 ioport:1000(size=256) memory:d1804000-d1804fff memory:d1800000-d1803fff

Here's ethtools output

Settings for eno1: Supported ports: [ TP ] Supported link modes: 10baseT/Half 10baseT/Full 100baseT/Half 100baseT/Full 1000baseT/Full Supported pause frame use: Symmetric Receive-only Supports auto-negotiation: Yes Supported FEC modes: Not reported Advertised link modes: Not reported Advertised pause frame use: Symmetric Advertised auto-negotiation: No Advertised FEC modes: Not reported Speed: 1000Mb/s Duplex: Full Auto-negotiation: off Port: Twisted Pair PHYAD: 0 Transceiver: internal MDI-X: Unknown Supports Wake-on: pumbg Wake-on: g Current message level: 0x00000033 (51) drv probe ifdown ifup Link detected: yes

Other Info Ubuntu 21.10 x86_64 , 5.13.0-35-generic, Lenovo Legion 5 15ARH05

1 Answer

Finally found a solution this might be helpful for others.

Known common bug

The solution is to pass a kernel parameter "pcie_aspm=off" to grub.

sudo nano /etc/default/grub
# Edit the following line and add pcie_aspm=off
GRUB_CMDLINE_LINUX_DEFAULT="splash pcie_aspm=off"
sudo update-grub

Sources:

Wired network extremely slow

Ubuntu 20.04 slow download speed (wired network)