Home/ Questions/Q 7874
Next
In Process

askthedev.com Latest Questions

Asked: 2024-09-25T17:28:12+05:30 In:

How can I resolve the issue of Network Manager not establishing a default route on my Ubuntu system?

I’ve been having this really annoying problem with my Ubuntu system lately that I’m hoping someone might be able to help me with. So, I’ve been using Network Manager to manage my connections, but for some reason, it just won’t set a default route for my network interface. I mean, it’s worked fine in the past, but now I’m stuck without internet because of this.

Here’s the situation: I recently updated my system, and ever since then, whenever I connect to my Wi-Fi or Ethernet, there’s no default route being set. I’ve tried disconnecting and reconnecting, rebooting my machine, and even resetting the Network Manager by restarting the service. Nothing seems to work! I checked my network configuration, and everything looks alright. The IP settings are correct, but it’s as if the Network Manager just refuses to do its job.

I’ve searched online, and I found a few threads where people suggest different things, like modifying connection files or messing with the routing table manually. But honestly, I’m a bit hesitant to dive into all of that because I don’t want to break something else. I also came across some posts mentioning it could be related to DHCP settings or certain plugins not being loaded, but I’m not sure where to start.

It’s super frustrating because I need to get connected to the internet for work and personal stuff. Just a few days ago, everything was running smoothly, and now, it feels like I’ve hit a brick wall. So, has anyone else run into this issue? Any tips or potential workarounds that could help? I’d really appreciate any insights you have. Do you think it might help to uninstall and reinstall the Network Manager, or would that just complicate things more? It’s just so perplexing how it can fail to establish a default route out of nowhere. Hoping someone out there has faced something similar and can share their experience!

Share

    Leave an answer

    You must login to add an answer.

    Need An Account,

    2 Answers






    1. Ubuntu Network Issue Help


      Network Manager Default Route Issue

      It sounds like you’re having a really annoying time with your Ubuntu system! Not being able to connect to the internet is super frustrating, especially when everything was fine before. Here are a few things you could try that might help fix the default route issue:

      1. Check Your Connection Settings

      Sometimes, the settings for your connection might have changed, especially after an update. Try going to the Network Manager settings and double-checking that the “Use this connection only for resources on its network” option is unchecked.

      2. Restart the Network Manager

      You mentioned you’ve done this, but just in case, you can run the following command in the terminal:

      sudo systemctl restart NetworkManager

      Then check if your default route gets set when you reconnect.

      3. Look at the DHCP Client Configuration

      The DHCP settings could indeed be the culprit. Open the file:

      /etc/NetworkManager/NetworkManager.conf

      Ensure that the following line is present:

      dns=dnsmasq

      Then, restart Network Manager again.

      4. Check the Routing Table

      You can view your current routing table with:

      ip route

      If there’s no default route (something like “default via x.x.x.x”), you can manually try adding one. Be careful with this step!

      sudo ip route add default via YOUR_GATEWAY_IP

      5. Last Resort: Reinstall Network Manager

      If nothing works, you might consider uninstalling and reinstalling Network Manager. But, this could complicate things more, so be cautious. The commands would typically be:

      sudo apt remove network-manager
      sudo apt install network-manager

      Just make sure you have a way to access the internet if things go haywire!

      I hope one of these suggestions helps you out. It seems like a fixable issue, and getting back online is definitely a priority. Good luck!



    2. If your Ubuntu system has stopped setting a default route after the recent update, there are several steps you can take to troubleshoot this issue. First, ensure that your Network Manager is managing the connection correctly. You can check the connection’s settings in the terminal using the command nmcli connection show to see if any other settings might be conflicting, such as static IP configurations. Additionally, check your routing table by executing route -n or ip route in the terminal. This can help identify if the routes are being added and whether there is an existing default route that might be causing conflicts. If you suspect DHCP might be the issue, verify that the DHCP client is functioning properly with systemctl status isc-dhcp-client or similar commands, depending on your DHCP client.

      If the problem persists, you can file a report with the changes made to your configuration files usually found in /etc/NetworkManager/system-connections/. Ensure the settings for your connection do not have any explicit ‘gateway’ fields filled if they shouldn’t be. Furthermore, if you feel comfortable exploring deeper, try resetting the Network Manager by renaming the /etc/NetworkManager/NetworkManager.conf file and restarting the service with sudo systemctl restart NetworkManager. Reinstalling the Network Manager is an option; however, it is generally a last resort and may complicate your configuration further than simply troubleshooting. Remember to back up any configuration files before making changes, as reverting back to a known state can help mitigate issues if something goes awry.


    Related Questions