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I have a weird connection problem. It occured a week ago. I am on Ubuntu 20.04. I can connect to router over wireless, but I can not browse web pages. Strange thing is that Windows, IOS, mobiles connect and browse. In order for me to browse the net, my brother has to upload some files to google drive within his Iphone, then connection problem disappears. It's the only solution for the time being. I didn't call ISP because I am the only one who has that issue. I can ping the domain addresses but traceroot fails to retrieve the route.

It appears to be a DNS issue, I tried different DNS servers both within the router and my laptop with no luck. What I don't understand is that why only my Linux machine is affected. I know there are many questions with the same title. I read most of them.

EDIT:

ls -al /etc/resolv.conf
lrwxrwxrwx 1 root root 29 Aug 31 23:15 /etc/resolv.conf -> ../run/resolvconf/resolv.conf

cat /etc/resolv.conf


Dynamic resolv.conf(5) file for glibc resolver(3) generated by resolvconf(8)


DO NOT EDIT THIS FILE BY HAND -- YOUR CHANGES WILL BE OVERWRITTEN


127.0.0.53 is the systemd-resolved stub resolver.


run "systemd-resolve --status" to see details about the actual nameservers.


nameserver 127.0.0.53
nameserver 8.8.8.8
nameserver 8.8.4.4

I also tried to connect from live iso nothing changed.

EDIT2:

From within router I ran a test. I get Ping default gateway fail error. When my brother starts uploading again it passes all tests.

Router's TP LINK TD-W9970. enter image description here

EDIT3:

Uploading a file to google drive from within my computer also keeps the connection online till the upload ends. Then I get locked out again.

kenn
  • 5,232

3 Answers3

5

In your case, /etc/resolv.conf is not pointing to systemd as expected. Therefore, please remove and recreated the link:

sudo rm -f /etc/resolv.conf
sudo ln -s /run/systemd/resolve/resolv.conf /etc/resolv.conf

Reboot and let us see:

ping -c3 8.8.8.8
ping -c3 www.ubuntu.com
chili555
  • 61,330
1

I found the fix after a week of struggling.

I noticed via

    netstat -pnt

that I have many SYN_SENT signals but no SYN/ACK

entering correct key words into search engines and checking out right Q/As directed me to @mcdizzle's answer

Appending the line net.ipv4.tcp_timestamps=0 into /etc/sysctl.conf

    sysctl -w net.ipv4.tcp_timestamps=0
    sysctl -p

made me on line. Thank you mcdizzle

kenn
  • 5,232
0

I have fixed my DNS issues by adding 8.8.8.8 and 8.8.4.4 to the list of DNS servers. My /etc/resolv.conf reads like:

# 127.0.0.53 is the systemd-resolved stub resolver.

nameserver 127.0.0.53
nameserver 8.8.8.8
nameserver 8.8.4.4
options edns0 trust-ad
search DOMAINS

I don't know if this is a canonical solution, but it works for me.

Francesc
  • 101