Score:0

Ubuntu

Machine with Static IP Address will not connect to the internet - 20.04

Chris Dutrow

3/1/24, 10:37 PM

Having a weird problem with configuring a public static IP address in Ubuntu 20.04. The computer will not connect to the internet. Cannot use web browser. Cannot ping 8.8.8.8

I checked over the settings I'm using many times. The IP address is correct, the gateway is correct and the netmask is correct. DNS settings are correct.

This is a brand new Ubuntu installation on a Mini PC box.

The hardware architecture is:

COX modem
- Swtich
  - Servers
  - (I tested a windows machine here to make sure there was not a problem with the IP address configuration)
  - The Ubuntu box (that won't connect to the internet)
  - Router
    - General office stuff
    - (I tested Ubuntu box here with DHCP to make sure there wasn't an issue with the hardware or cable)

I also tested these things:

Made sure the ethernet cable and network hardware worked by hooking Ubuntu box up to my router and using DHCP internet - internet worked fine on this Ubuntu box when using DHCP and my router.
Made sure the static IP worked by configuring the same settings on a windows box that I have. That box was able to successfully get internet with that IP address hooked up using the same cable and same switch
Tried disabling IPv6 (I think this is how windows does it if I don't explicitly supply a manual IPv6)

I'm not really sure what else to do. I don't even know how to trouble shoot this. My guess is there is some obscure setting I need to correct, or there is some default part of the Ubuntu installation that is blocking the connection.

Below are the screenshots of the setup. As you can see, the specific configuration is:

Public static IP: XXX.XXX.37.62
Net mask: 255.255.255.240
Gateway: XXX.XXX.37.49
DNS servers 68.105.28.16, 68.105.29.16 (I also tried with 8.8.8.8, 8.8.4.4)
I set "routes" to automatic. I'm not sure if that is right. The windows machines did not ask me to configure this.

Scrolled down to show the routes setting:

411

0 + 14

static-ip

waltinator

3/2/24, 12:06 AM

Please read https://askubuntu.com/help/how-to-ask and https://askubuntu.com/help/formatting Your tale has none of the details that would help us help you.

Chris Dutrow

3/2/24, 2:06 PM

@Nmath This is a public IP. Not a static IP on a home network. I will update the question with more details.

Chris Dutrow

3/2/24, 3:35 PM

@user68186 Thanks for the suggestion. I tried this just now, but it did not work.

Chris Dutrow

3/6/24, 9:31 PM

@user68186 Netmask to 255.255.255.0 did not work. I also actually exchanged out the computer for another one just to make sure it wasn't some weird hardware issue. I don't have it connected through an router, its connected directly into a swtich that is connected to the cable modem. I got the gateway address from my ISP. All of the information with this configuration works on the windows boxes, but not on Ubuntu so its likely not an issue with using the wrong gateway or netmask or something like that. Is there something I should be putting under "routes"? I still have that as automatic.

user68186

3/6/24, 10:18 PM

Please update your question with the new information about your switch-cable modem setup and what you have with with the ISP.

Chris Dutrow

3/7/24, 12:05 PM

@user68186 I have the setup outlined in the question under "The hardware Architecture is:". The information from the ISP is the: Static IP (XXX.XXX.37.62), Net mask (255.255.255.240), Gateway (XXX.XXX.37.49), and DNS servers (68.105.28.16, 68.105.29.16). Its pretty straightforward. I figure there might be some checkbox or setting with Unbuntu somewhere that needs to be set because all this works fine in an identical setup on my windows machines. Is there some other information you want that is not there?

user68186

3/7/24, 4:33 PM

Adding new information in the comments are not sufficient. The comments are our channel for asking for clarifications. As a questioner, you should edit your question and put all relevant information in the question. From your question it is not clear if this is a home or office set up, as well as the information you shared in the last comment. The question may be closed for the lack of details and clarity.

Chris Dutrow

3/7/24, 8:13 PM

@user68186 I think there might be a misunderstanding here. All of the information I added in the comments, was already in the question. I did make a revision last week when people asked for more clarity - outlining the architecture.

Thomas Ward

3/7/24, 8:32 PM

If you are behind a router, chances are you are *not* going to be able to put a static public IP in range unless it's a properly configured Business-grade router that is configured to *accept* public routes. Most commercial grade routers tend to use NAT to map public to private IP address ranges and most gateways are NOT capable of handing off public IP to a subnetted device directly on the link withotu it being a compatible device and most aren't.

Chris Dutrow

3/8/24, 12:46 AM

@ThomasWard - Its not behind a router. Also, the same exact settings ans setup work properly when using a windows machine.

Thomas Ward

3/8/24, 3:19 PM

@ChrisDutrow one consideration is that some gateways ("modems" in this case) are static locked for routes because it identified that MAC address ABC and then locks to that for the duration of the ARP cache time on the device itself. Network Manager is also not the best tool at *reloading* your configuration so you would have to plug/unplug the device every time

Chris Dutrow

3/8/24, 9:05 PM

@ThomasWard - As far as the gateway, I suspect this isn't the case because I was able to switch around the windows machine IP addresses at will. I have three set up now with public static IP addresses. I will try unplugging and plugging in the cable itself next time though, thanks.

Thomas Ward

3/8/24, 11:51 PM

DO you *need* 20.04 or can you boot to a 22.04 live environment on the desktop and test/try it? Just to make sure it's not the 20.04 environment.

Chris Dutrow

3/9/24, 3:13 PM

@ThomasWard - I don't any particular version. I'm just trying to set up a remote desktop so an overseas guy who works for me can use it for code development. I can try that. This is actually the second Ubuntu machine that I've have this problem with so I can't help but think there is some setting or checkbox or something somewhere, otherwise more people would be having this issue.

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