[SOLVED]Internet speed becomes slower after PC is waking up from sleep

XDarkAngelX · Yesterday 06:18:56

I am having an issue where after my pc wakes up from sleep the internet speed becomes 600Mbit instead of the normal 900Mbit, when the issue happens I see lots of Retr when I test the speed using iperf3
I am connected to the route using an Ethernet cable, and the local LAN speed seems to be ok and stays at 940Mbit even after sleep.
I have managed to narrow it down that the issue only happens after the pc wakes from sleep and it only happens after 30 mins of sleep or just putting it to sleep and waking it won't cause the issue.
The only I found that fixes the issue is either reboot the router or assign new IP to the pc in the router.

Any idea what could be causing this issue ? any idea what to look for ?
Also I don't think this issue started recently I think that just recently I have managed to understand when it happens and that it is local to only this pc

kernel 7.2.6-arch2-1
KDE Plasma Version 6.7.5
KDE Frameworks version 6.30.0
Qt Version 6.11.2
Motherboard : TUF GAMING B550M-PLUS (WI-FI)

Last edited by XDarkAngelX (Today 09:44:46)

-thc · Yesterday 06:43:55

Can you check if the speed recovers after resume when you unplug the Ethernet cable from the PC for 10 seconds?

Last edited by -thc (Yesterday 06:44:13)

XDarkAngelX · Yesterday 06:50:36

from my previous tests the speed didn't recover when I have unplugged the Ethernet cable from my PC , but I can try later today again to verify for sure

seth · Yesterday 07:29:43

when the issue happens I see lots of Retr when I test the speed using iperf3

Have you checked that the count is indeed higher than normal?

The only I found that fixes the issue is either reboot the router or assign new IP to the pc in the router.

it only happens after 30 mins of sleep

Dual booting windows?

Please post your complete system journal for such boot eg.

sudo journalctl -b -1 | nc termbin.com 9999

for the previous ("-1") one so we can know the involved hardware, what and how is actually configuring your network and what happens around the sleep and what that sleep looks like (S3 or s2idle)

XDarkAngelX · Yesterday 08:11:37

ok reproduced the issue again , it seems 10 mins of sleep is enough to trigger the issue
un-plugging the Ethernet cable for 10 seconds doesn't help to resolve it.

I am not dual booting windows , never installed windows on this machine

output of

sudo journalctl -b -1 | nc termbin.com 9999

https://termbin.com/7zhh

also added the output of the current boot where I have reproduced it a few mins ago

sudo journalctl -b | nc termbin.com 9999

https://termbin.com/e47m6

XDarkAngelX · Yesterday 08:28:05

Have you checked that the count is indeed higher than normal?

it is indeed higher than normal , normally I get

[ ID] Interval           Transfer     Bitrate         Retr
[  5]   0.00-60.01  sec  5.18 GBytes   741 Mbits/sec  117            sender
[  5]   0.00-60.00  sec  5.17 GBytes   740 Mbits/sec                  receiver

while when the issue happens I get

[ ID] Interval           Transfer     Bitrate         Retr
[  5]   0.00-60.02  sec  3.52 GBytes   504 Mbits/sec  493            sender
[  5]   0.00-60.00  sec  3.52 GBytes   504 Mbits/sec                  receiver

-thc · Yesterday 08:35:41

Did you enable jumbo frames?

ספט 20 12:37:18 Arch-Home kernel: r8169 0000:06:00.0 eth0: jumbo features [frames: 16362 bytes, tx checksumming: ko]

XDarkAngelX · Yesterday 09:07:04

not sure w hat are jumbo frames are
From what I could gather my mtu is set to 1500 and that should mean that jumbo frames are not enabled.
I have tried to set the mtu to 9000 but it doesn't seem to affect the issue I am having

seth · Yesterday 16:46:48

oct 20 12:37:10 archlinux kernel: Linux version 7.2.6-arch2-1 (linux@archlinux) (gcc (GCC) 16.2.1 20260810, GNU ld (GNU Binutils) 2.47) #1 SMP PREEMPT_DYNAMIC Mon, 14 Sep 2026 22:41:30 +0000
oct 20 12:37:18 Arch-Home kernel: r8169 0000:06:00.0 eth0: RTL8125B, 24:4b:fe:48:95:dd, XID 641, IRQ 95
oct 20 12:37:18 Arch-Home kernel: r8169 0000:06:00.0 eth0: jumbo features [frames: 16362 bytes, tx checksumming: ko]
oct 20 12:37:18 Arch-Home kernel: r8169 0000:06:00.0 enp6s0: renamed from eth0
oct 20 12:37:19 Arch-Home kernel: Realtek Internal NBASE-T PHY r8169-0-600:00: attached PHY driver (mii_bus:phy_addr=r8169-0-600:00, irq=MAC)
oct 20 12:37:20 Arch-Home kernel: r8169 0000:06:00.0 enp6s0: Link is Down
oct 20 12:37:23 Arch-Home kernel: r8169 0000:06:00.0 enp6s0: Link is Up - 1Gbps/Full - flow control rx/tx
oct 20 16:20:10 Arch-Home kernel: r8169 0000:06:00.0 enp6s0: Link is Down
oct 20 16:20:21 Arch-Home kernel: r8169 0000:06:00.0 enp6s0: Link is Up - 1Gbps/Full - flow control rx/tx
oct 20 17:16:38 Arch-Home kernel: r8169 0000:06:00.0 enp6s0: Link is Down
oct 20 17:16:51 Arch-Home kernel: r8169 0000:06:00.0 enp6s0: Link is Up - 1Gbps/Full - flow control rx/tx
oct 21 05:32:48 Arch-Home kernel: r8169 0000:06:00.0 enp6s0: Link is Down
oct 21 05:32:48 Arch-Home systemd[1]: Reached target Sleep.
oct 21 10:42:13 Arch-Home systemd[1]: Stopped target Sleep.
oct 21 10:42:13 Arch-Home kernel: Realtek Internal NBASE-T PHY r8169-0-600:00: attached PHY driver (mii_bus:phy_addr=r8169-0-600:00, irq=MAC)
oct 21 10:42:13 Arch-Home kernel: r8169 0000:06:00.0 enp6s0: Link is Down
oct 21 10:42:16 Arch-Home kernel: r8169 0000:06:00.0 enp6s0: Link is Up - 1Gbps/Full - flow control rx/tx
oct 21 16:11:18 Arch-Home kernel: r8169 0000:06:00.0 enp6s0: Link is Down
oct 21 16:11:50 Arch-Home kernel: r8169 0000:06:00.0 enp6s0: Link is Up - 1Gbps/Full - flow control rx/tx
oct 21 16:16:34 Arch-Home kernel: r8169 0000:06:00.0 enp6s0: Link is Down
oct 21 16:17:04 Arch-Home kernel: r8169 0000:06:00.0 enp6s0: Link is Up - 1Gbps/Full - flow control rx/tx
oct 21 16:17:56 Arch-Home kernel: r8169 0000:06:00.0 enp6s0: Link is Down
oct 21 16:17:56 Arch-Home systemd[1]: Reached target Sleep.
oct 21 16:18:12 Arch-Home systemd[1]: Stopped target Sleep.
oct 21 16:18:12 Arch-Home kernel: Realtek Internal NBASE-T PHY r8169-0-600:00: attached PHY driver (mii_bus:phy_addr=r8169-0-600:00, irq=MAC)
oct 21 16:18:12 Arch-Home kernel: r8169 0000:06:00.0 enp6s0: Link is Down
oct 21 16:18:15 Arch-Home kernel: r8169 0000:06:00.0 enp6s0: Link is Up - 1Gbps/Full - flow control rx/tx
oct 22 01:53:18 Arch-Home kernel: r8169 0000:06:00.0 enp6s0: Link is Down
oct 22 01:53:19 Arch-Home systemd[1]: Reached target Sleep.
oct 22 08:05:03 Arch-Home systemd[1]: Stopped target Sleep.
oct 22 08:05:03 Arch-Home kernel: Realtek Internal NBASE-T PHY r8169-0-600:00: attached PHY driver (mii_bus:phy_addr=r8169-0-600:00, irq=MAC)
oct 22 08:05:03 Arch-Home kernel: r8169 0000:06:00.0 enp6s0: Link is Down
oct 22 08:05:06 Arch-Home kernel: r8169 0000:06:00.0 enp6s0: Link is Up - 1Gbps/Full - flow control rx/tx
oct 22 08:07:13 Arch-Home kernel: r8169 0000:06:00.0 enp6s0: Link is Down
oct 22 08:08:01 Arch-Home kernel: r8169 0000:06:00.0 enp6s0: Link is Up - 1Gbps/Full - flow control rx/tx
oct 22 08:08:28 Arch-Home kernel: r8169 0000:06:00.0 enp6s0: Link is Down
oct 22 08:08:50 Arch-Home kernel: r8169 0000:06:00.0 enp6s0: Link is Up - 1Gbps/Full - flow control rx/tx
oct 22 08:12:47 Arch-Home kernel: r8169 0000:06:00.0 enp6s0: Link is Down
oct 22 08:12:50 Arch-Home kernel: r8169 0000:06:00.0 enp6s0: Link is Up - 1Gbps/Full - flow control rx/tx
oct 22 08:12:51 Arch-Home kernel: r8169 0000:06:00.0 enp6s0: Link is Down
oct 22 08:12:54 Arch-Home kernel: r8169 0000:06:00.0 enp6s0: Link is Up - 1Gbps/Full - flow control rx/tx
oct 22 08:13:00 Arch-Home kernel: r8169 0000:06:00.0 enp6s0: Link is Down
oct 22 08:13:04 Arch-Home kernel: r8169 0000:06:00.0 enp6s0: Link is Up - 1Gbps/Full - flow control rx/tx
oct 22 08:13:09 Arch-Home kernel: r8169 0000:06:00.0 enp6s0: Link is Down
oct 22 08:13:12 Arch-Home kernel: r8169 0000:06:00.0 enp6s0: Link is Up - 1Gbps/Full - flow control rx/tx
oct 22 08:13:13 Arch-Home kernel: r8169 0000:06:00.0 enp6s0: Link is Down
oct 22 08:13:18 Arch-Home kernel: r8169 0000:06:00.0 enp6s0: Link is Up - 1Gbps/Full - flow control rx/tx
oct 22 08:23:51 Arch-Home kernel: r8169 0000:06:00.0 enp6s0: Link is Down
oct 22 08:23:51 Arch-Home systemd[1]: Reached target Sleep.
oct 22 23:03:04 Arch-Home systemd[1]: Stopped target Sleep.
oct 22 23:03:04 Arch-Home kernel: Realtek Internal NBASE-T PHY r8169-0-600:00: attached PHY driver (mii_bus:phy_addr=r8169-0-600:00, irq=MAC)
oct 22 23:03:04 Arch-Home kernel: r8169 0000:06:00.0 enp6s0: Link is Down
oct 22 23:03:07 Arch-Home kernel: r8169 0000:06:00.0 enp6s0: Link is Up - 1Gbps/Full - flow control rx/tx

The carrier flicker is you (ie. you just re-plugged the cable a couple of times)?

Instead of rebooting, is it sufficient to restart
1. your user session (GUI)
2. NetworkManager
3. nmbd
?

XDarkAngelX · Today 06:54:28

I guess the carrier flicker could be me re-plugging the cable yes, but odd thing that happened to me today when I have tried to reproduce the issue the speed got stuck suddenly on 100Mbit instead of 1Gbit speed which only resolved when I changed the port on the router that the pc is connected to.

Instead of rebooting, is it sufficient to restart
1. your user session (GUI)
2. NetworkManager
3. nmbd
?

the only thing that solves the issue currently is mapping new ip to the pc or rebooting the router, I have not found anything on the PC itself that I can do to resolve the issue , so no to all , even rebooting the pc doesn't help

cryptearth · Today 07:07:20

what router do you have?
can you manage its interface?
have you checked for firmware updates?
have you tried a full factory reset?

-thc · Today 07:08:45

It's highly likely that the cause is the Ethernet switch component inside your router.

If you have a small 4/6/8-port Gigabit switch at hand you could test plugging that between your PC and the router.

XDarkAngelX · Today 09:38:26

The issue seems to be un-related to putting the computer to sleep, I can reproduce the same issue with un-plugging the Ethernet cable for 10 mins and reconnecting it.
I have also now tried to also connect a different pc I have(also with Archlinux) to the same Ethernet cable and couldn't reproduce the same issue with it.
I do actually have a Gigabit switch at hand and connecting the PC using it , reproduces the same exact issue.

So the issue is something with the router that doesn't like about my PC.
I have digged some more and now after I have removed the static ip allocation for my pc in the router the issue went away.

Thanks everyone for the help ! can't reproduce the issue now after removing the static ip allocation

Arch Linux

#1 Yesterday 06:18:56

[SOLVED]Internet speed becomes slower after PC is waking up from sleep

#2 Yesterday 06:43:55

Re: [SOLVED]Internet speed becomes slower after PC is waking up from sleep

#3 Yesterday 06:50:36

Re: [SOLVED]Internet speed becomes slower after PC is waking up from sleep

#4 Yesterday 07:29:43

Re: [SOLVED]Internet speed becomes slower after PC is waking up from sleep

#5 Yesterday 08:11:37

Re: [SOLVED]Internet speed becomes slower after PC is waking up from sleep

#6 Yesterday 08:28:05

Re: [SOLVED]Internet speed becomes slower after PC is waking up from sleep

#7 Yesterday 08:35:41

Re: [SOLVED]Internet speed becomes slower after PC is waking up from sleep

#8 Yesterday 09:07:04

Re: [SOLVED]Internet speed becomes slower after PC is waking up from sleep

#9 Yesterday 16:46:48

Re: [SOLVED]Internet speed becomes slower after PC is waking up from sleep

#10 Today 06:54:28

Re: [SOLVED]Internet speed becomes slower after PC is waking up from sleep

#11 Today 07:07:20

Re: [SOLVED]Internet speed becomes slower after PC is waking up from sleep

#12 Today 07:08:45

Re: [SOLVED]Internet speed becomes slower after PC is waking up from sleep

#13 Today 09:38:26

Re: [SOLVED]Internet speed becomes slower after PC is waking up from sleep

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