Internet stops working after some time

[jeremyy44]

Hi,

So recently I have been getting some problems with my server's internet.
So my server is on Ubuntu Server 20.04 and whats been happening is that my internet will be fine and working for a while like for exemple it has been working fine for the past week but all of a suden with no good reason or me doing anything it stops. Im noticing it stop since im using Healthcheck.io to monitor my cron jobs and on of them is updating my subdomain wan ip so it needs internet acces to work and when it dosnt I get notifies. The cron job works every hour.
Im using NetworkManager to manage my ip adresse since im using Cockpit as a web GUI to manage my server.
Lan acces is working perfectly fine. Even the DNS server running on it works fine and my devices that only use my servers ip has their dns can connect to the internet. Using PiHole as a DNS server but not as a DHCP server.
Plex also works for outside uses like if im on LTE I can connect and watch anything fine.
I can even have a ssh session work on LTE using my wan ip but my server cannot download any packages, update, run a speedtest.
Pinging 8.8.8.8 also works

This the result of ifconfig

enp9s0: flags=4163<UP,BROADCAST,RUNNING,MULTICAST>  mtu 1500
        inet 192.168.2.10  netmask 255.255.255.0  broadcast 192.168.2.255
        inet6 fe80::e26e:da2f:7003:6cab  prefixlen 64  scopeid 0x20<link>
        ether b4:2e:99:9a:ed:3f  txqueuelen 1000  (Ethernet)
        RX packets 3219472  bytes 997293081 (997.2 MB)
        RX errors 0  dropped 0  overruns 0  frame 0
        TX packets 2562698  bytes 5032040808 (5.0 GB)
        TX errors 0  dropped 0 overruns 0  carrier 0  collisions 0
        device interrupt 60  base 0x1000

 

[jeremyy44]

And now for some reason its back up but I know it wont be permanant. And I didnt do anything

 

[DexTheDog]

What are you using your server for what type of ethernet card are you using could it be a problem with your internet.

 

[jeremyy44]

What are you using your server for what type of ethernet card are you using could it be a problem with your internet.

Im using my server for plex, Nextcloud, PiHole and bitwarden. Im using the integrated network card on my motherboard and no its not my internet since everything else works fine even when my servers internet dosnt.

 

[dcbrown73]

Hi,

So recently I have been getting some problems with my server's internet.
So my server is on Ubuntu Server 20.04 and whats been happening is that my internet will be fine and working for a while like for exemple it has been working fine for the past week but all of a suden with no good reason or me doing anything it stops. Im noticing it stop since im using Healthcheck.io to monitor my cron jobs and on of them is updating my subdomain wan ip so it needs internet acces to work and when it dosnt I get notifies. The cron job works every hour.
Im using NetworkManager to manage my ip adresse since im using Cockpit as a web GUI to manage my server.
Lan acces is working perfectly fine. Even the DNS server running on it works fine and my devices that only use my servers ip has their dns can connect to the internet. Using PiHole as a DNS server but not as a DHCP server.
Plex also works for outside uses like if im on LTE I can connect and watch anything fine.
I can even have a ssh session work on LTE using my wan ip but my server cannot download any packages, update, run a speedtest.
Pinging 8.8.8.8 also works

Let me ensure I understand what you're saying.

When everything stops working, Plex and other connections still work, but trying to download something or connect to some outside host from the afflicted server fails?

You can ping 8.8.8.8 even when it's not working?

Sounds like a DNS issue. I realize you said your DNS is working fine, but based on what you said. It seems like your Internet is fine, your ability to resolve names properly isn't. Whether this is a DNS server issue, or your NetworkManager (or whatever else you maybe doing) is blowing up your resolver settings.

 

[jeremyy44]

Let me ensure I understand what you're saying.

When everything stops working, Plex and other connections still work, but trying to download something or connect to some outside host from the afflicted server fails?

You can ping 8.8.8.8 even when it's not working?

Sounds like a DNS issue. I realize you said your DNS is working fine, but based on what you said. It seems like your Internet is fine, your ability to resolve names properly isn't. Whether this is a DNS server issue, or your NetworkManager (or whatever else you maybe doing) is blowing up your resolver settings.

Yes you are understanding everything correctly

And I would think its DNS to since I have renderer: NetworkManager set in my netplan config file but even when commenting it out and going back to using networkd instead I still see the issue appears.

Like right now for exemple everything is working fine.

And as you can see from the Healthcheck.io logs its on a daily basis.
And its always failing around every 12h or so which is also weird ngl. (when it fails is when its sending me a email)

 

[dcbrown73]

Something is making network changes to your machine. Dynamic DNS or something. I would focus on any software that touches network configurations that you have running or scheduled in a cronjob.