Ethernet has very slow speeds and timeouts every 20 minutes until I restart NetworkManager

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21

portmaster ultimately was what i needed I think. Before it finished setting up it sent a notification:

Portmaster has detected that websites may load slower because DNS queries are currently slower than expected. You may want to switch your DNS provider or enable using expired DNS cache entries for better performance.

I’ve never changed DNS provider before but that with other things I’ve read both here and online lead me to believe the modem change might have changed my DNS. I’m not sure but at least I have a better idea.

This Portmaster application seems really great and is quickly answering questions I’ve had for awhile that I didn’t know how to ask. Something I needed, so thank you for that suggestion especially.

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22

Modems (or rather, usually Routers) have the ability to set DNS.
And, if you have never actively set your DNS on your computer system … thats likely the DNS it is using.
I generally encourage people to set it to something other than whatever the ISP provides.
For speed and security reasons.
There are a number of factors when deciding what DNS to use, and a number of ways to implement that decision.
For now I will assume you can and will use your router to do this …
but if you are interested I wrote a quick setup of how I use systemd-resolved here:
After laptop resumes from Standby I lose DNS - #2 by cscs

Anyways moving on … heres a little script to test and rank some popular DNS providers:
(Edit - added in link to dedicated thread)

Old pasted script 
#!/usr/bin/env bash
#
# dns speed test
#
if [[ -z "$DOMAIN" ]]; then
    DOMAIN=wikipedia.org
fi;
CURRENTDNS=$(dig "$DOMAIN" | grep SERVER | awk -F'[)(]' '{print $2}')
if [[ -z "$SKIP" ]]; then
    echo
    echo " Test common resolvers by calculating average response times of 3 queries."
    echo
    annc() {
        echo
        echo " DNS Primary  Secondary"
        echo
        echo " Adguard 94.140.14.14 94.140.15.15"
        echo " CleanBrowsing 185.228.168.9 185.228.169.9"
        echo " Comodo 8.26.56.26 8.20.247.20"
        echo " Control-D 76.76.2.2 76.76.10.2"
        echo " Cloudflare 1.1.1.1 1.0.0.1"
        echo " Google 8.8.8.8 8.8.4.4"
        echo " Neustar 156.154.70.2 156.154.71.2"
        echo " NextDNS 45.90.28.97 45.90.30.97"
        echo " OpenDNS 208.67.222.222 208.67.220.220"
        echo " Quad9 9.9.9.9 149.112.112.112"
        echo
    }
    printf '%*s\n' "${COLUMNS:-$(tput cols)}" '' | tr ' ' -
    annc | column -tL
fi;
if [[ -n "$TESTDNS" ]]; then
    echo "Custom Test DNS $TESTDNS"
fi
printf '%*s\n' "${COLUMNS:-$(tput cols)}" '' | tr ' ' -
echo
while true; do
    read -p " Do you wish to flush the DNS cache? " yn
    case $yn in
        [Yy]* ) resolvectl flush-caches; break ;;
        [Nn]* ) break ;;
        * ) echo -e "\n Please answer yes or no.\n" ;;
    esac
done
echo
echo "Current DNS $CURRENTDNS"
for reps in {1..3}
do
    dig "$DOMAIN" | awk '/time/ {print $4 " ms"}'
    sleep 1
done | awk '/ms/ {sum+=$1} END {print "Avg time: ",sum/3, " ms"}'
echo
if [[ -z "$SKIP" ]]; then
    rank() {
        for resolver in "Adguard 94.140.14.14" "CleanBrowsing 185.228.168.9" "Comodo 8.26.56.26" "Control-D 76.76.2.2" "Cloudflare 1.1.1.1" "Google 8.8.8.8" "Neustar 156.154.70.2" "NextDNS 45.90.28.97" "OpenDNS 208.67.222.222" "Quad9 9.9.9.9";
        do
            echo "$resolver"
            for reps in {1..3}
            do
                dig "$DOMAIN" "@${resolver#* }" | awk '/time/ {print $4 " ms"}'
                sleep 1
            done | awk '/ms/ {sum+=$1} END {print "Avg time: ",sum/3, " ms"}'
            echo
        done
    }
    rank;
fi;
if [[ -n "$TESTDNS" ]]; then
    echo "Custom Test DNS $TESTDNS"
    for reps in {1..3}
    do
        dig "$DOMAIN" "@$TESTDNS" | awk '/time/ {print $4 " ms"}'
        sleep 1
    done | awk '/ms/ {sum+=$1} END {print "Avg time: ",sum/3, " ms"}'
    echo
fi
exit

(save, mark executable, run … it will give you an average response time for each)
Note: It uses dig which is provided by the package bind.

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23

The from field lists the source, in this case your computer, it has rapid response times because it is local.

The first line tells us that the default route to the rest of the network (eg internet) is 107.11.224.1 and that is is the first one to try. The second line lists the network your machine is in. It is the way the machine can tell what is local to it and what it needs to be sent to the gateway. The /20 on the end means that there is a maximum of 4096 hosts that can exist in that network.

Your experience pinging the gateway and it responding on one moment en then won’t respond at all is valuable data. Since the ping to google seems to always work this could be a indicator that the gateway/infrastructure of the ISP has some difficulty responding to the requests.

[lattrommi@taichi ~]$ ping -c 3 107.11.224.0/20
ping: 107.11.224.0/20: Name or service not known

This fails because ping command expects a specific address and the value is a network.
This is the correct response of the command used and not relevant.

[lattrommi@taichi ~]$ ping -c 3 107.11.224.0
PING 107.11.224.0 (107.11.224.0) 56(84) bytes of data.
From 107.11.230.54 icmp_seq=1 Destination Host Unreachable

This fails because the host is not valid, eg your computer cannot reach it, this is the correct response and not relevant in this case.

Changing the DNS server is a valid option. Since the ISP assigns a default value through DHCP & sets their own DNS servers as the default and your experience (portmaster hinting at this to) is not stellar there are a few way’s to check / change / test.

In Firefox there is a option to use DNS over HTTPS. Using this option is easy to turn on, accept the default, restart browser and test. The rollback is easy to, just change the option.

In the KDE network settings for the connection there is a option to set the DNS resolver yourself instead of accepting the default one your ISP assigns. If inputting numbers is hard this can be the more difficult option to get right and to fix if this does not work. Using the script above will give insight into what is possible for replacements DNS servers.

1 Like
24

thanks to both of you for all the information, I appreciate it more than I can say!

things have not worked out well for me unfortunately. i have nor had decently working internet on the computer since I last commented.

I tried changing my DNS but could not seem to get rid of the ISP DNS. any changes I made would not take effect on rebooting or any other way.

I factory reset the modem and still nothing.

I’m not using a router right now and was not able to do anything with the modem beyond power cycling and the factory reset. I tried reconnecting my obselete router but couldn’t login into it, I think it might have stopped working too.

I was able to USB tether my phone for internet, which helped me research more easily for awhile. the phone service company, Verizon, uses throttling deprioritization for lower class customers after their data caps are met, which drops the speed of the connection to 600kbps (they say, much lower in reality) and is just as useless as the internet in my initial problem. I found other articles likely related. I may add them if I can before the post gets auto-closed. not easy to share from PC to phone, not with my circumstances and this budget phone at least.

I did re-learn that the Realtek Ethernet device is buggy, as was mentioned. (I can’t see who said it while replying on my phone) and looking into it more, I found a 2 year old Reddit thread with people having the same problems, with the same equipment, in a windows environment and it was still getting comments as of last week. my current working theory is that the ethernet NIC is junk and i need to return my motherboard.

oddly enough I was able to log on to with windows again, something I haven’t been able to do inover a month. I read that occasionally, logging into windows and updating the driver there is sometimes a fix but not in my case. despite the specs of my PC, windows was slow and too painful to to use for anything, even moreso than it usually is. it took a minute and a half to open the task manager with ctrl+shift+escape because of all the background stuff happening for updates and telemetry or whatever.

i blacklisted r8169 and installed r8168 again, undid that, tried the reverse, undid that. wandered around the systemd labyrinth pointlessly to see if anything looked wrong, tried reinstalling all network related things I could, created a new user and tested with that, took an SSD from another (older) system with manjaro on it and ran it in CSM mode and still no connection nothing.

I’ve messed with so many settings at this point, I doubt anything can be fixed because of some setting I’d changed and forgot to revert.

I’m going to try one more thing and see if I can connect from from a live USB. if that doesn’t help I’ll reinstall manjaro. next option is to RMA the board.

thanks again for taking a look and all the tips and suggestions!

25

This has been resolved. The modem provided by my ISP had an internal battery, not accessible to the end user in a simple way, was steadily failing. It was replaced a little over 24 hours ago and since then I have had no issues. If you are reading this and having similar problems, remember: don’t trust your ISP.

Those who offered support, I have learned a lot from you and feel I now have better direction towards learning more. I cannot thank you enough.

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26

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