Networking Question

[Dockhead]

For you network geeks --


I have just managed to connect my ship's computer, a fixed-mount low power PC, to my boat network via Ethernet. Using a spare port on the Go Free WiFi router.



It works great and gives me full radar control (using the excellent OpenCPN plug in) besides all of the network data.


The only problem is that if I simultaneously connect to Internet using the ship's computer's wifi, one or the other won't work -- there is some kind of collision. I have to disable the Ethernet card in order to download GRIBs.


Anyone have a tip on how to resolve this?

[DotDun]

What OS?

The OS is prioritizing the Ethernet higher than Wi-Fi. You may be able to set the default gateway on the Ethernet to the same as Wi-Fi, or re-prioritize the interfaces in the route table. Assuming there is only 1 network on the Ethernet, this will work fine.

[Reefmagnet]

What's likely happening is that when you request data from the Internet, the request is being sent to your wired connection instead of the wifi so it never reaches the destination. First check is that the networks aren't on the same subnet. Once this is verified check your dns and gateway configuration.You want to make sure requests to to the internet are sent to the wifi,

Assuming you use windows, "Ping" and "Tracert" commands typed into a command window can help you troubleshoot. "nslookup" is also a good tool, but is a little more advanced to use.

[pcmm]

what is your wifi IP address? what is your wired IP address? are they on the same subnet?

[reduc]

You haven't specified OS so I will assume Windows 10. I'd guess your routes are being replaced depending on which network you connect to and in which order.

Is there a reason the Wifi router can't provide the ethernet connection to your PC rather than having the PC connect directly to the ethernet wifi? That would probably be the easiest solution.

Outside of that you will probably have to add some static routes (a relatively easy process).

If you can show your IPv4 routing tables when connected to:
1. Ship network only
2. Internet wifi only
3. Both

I could probably tell you what you need to add. To see your routing tables:

1. In the "Type here to search" box next to the lower left windows button on the screen type "cmd" - this will open a command prompt.

2. In the command prompt window type "route print" - a page or so of output will appear. Find the "IPv4 Route Table" section and copy the output for the scenarios above if you want to add static routes.

3. In the above do not include the quotes in your typing.

[pcmm]

Assuming both the wifi and wired connections aren't on the same subnet, you have a routing issue. by default your PC will assign a route to 0.0.0.0 (every network it doesn't know about) to the first LAN connection that you connected (or the preferred one) you need to add a route to your routing table to define WHICH LAN connection to use to get to the internet.

[Dockhead]

Originally Posted by DotDun

What OS?

The OS is prioritizing the Ethernet higher than Wi-Fi. You may be able to set the default gateway on the Ethernet to the same as Wi-Fi, or re-prioritize the interfaces in the route table. Assuming there is only 1 network on the Ethernet, this will work fine.

Win 10


Thanks -- I'll have a look at that.

[Unregistered-1]

Check that you don't have a device connected to BOTH wifi AND ethernet.

Also make sure there is only ONE device on the network offering network addresses - this should be your internet gateway device - all other devices should connect as clients and use auto mode (DHCP) to get their configuration.

[Dockhead]

Originally Posted by reduc

You haven't specified OS so I will assume Windows 10. I'd guess your routes are being replaced depending on which network you connect to and in which order.

Is there a reason the Wifi router can't provide the ethernet connection to your PC rather than having the PC connect directly to the ethernet wifi? That would probably be the easiest solution.

Outside of that you will probably have to add some static routes (a relatively easy process).

If you can show your IPv4 routing tables when connected to:
1. Ship network only
2. Internet wifi only
3. Both

I could probably tell you what you need to add. To see your routing tables:

1. In the "Type here to search" box next to the lower left windows button on the screen type "cmd" - this will open a command prompt.

2. In the command prompt window type "route print" - a page or so of output will appear. Find the "IPv4 Route Table" section and copy the output for the scenarios above if you want to add static routes.

3. In the above do not include the quotes in your typing.

Thank you -- this is really helpful.


I would prefer not to route the connection to the boat network through any other router.


Basically, what I have is the Navico "WiFi One" module (sometimes referred to as "Go Free"), which is connected to the boat network by Ethernet. The nav table Zeus plotter has a switch in it, to which the radar and the other plotter are connected, as well as the WiFi One.


The WiFi one is a wifi router. As long as I don't have any other network adapter on the boat computer connected to anything, the Ethernet connection works fine. The network identifies as "GoFree Wifi 21D2". I get radar as well as network data (in NMEA 0183 form), and I can control the radar from the boat computer using the OpenCPN Navico radar plug-in.


I could do as you suggest and connect the WiFi One to a Huawei router instead of to the boat computer, and plug the boat computer into the router. But this would require the router to be on -- and I don't need it offshore. Also it would be somewhat complicated to use a wifi Internet connection (rather than the mobile phone connection which the Huawei B593 makes itself).



I don't use Internet much on the boat computer because I don't do general computing on it, but I do need to connect from time to time to download GRIBs, update software, load charts, etc. I could just unplug the Ethernet cable whenever I do so, which is what I've been doing. But this network problem is a puzzle which I would like to solve just on principle!


I pulled up the routing table as you suggested. It looks like this:







So the idea is to create a Persistent Route to the Go Free router, which will be unaffected by other network connections?

[Sailorboy FIN]

Originally Posted by Dockhead

Thank you -- this is really helpful.


I would prefer not to route the connection to the boat network through any other router.


Basically, what I have is the Navico "WiFi One" module (sometimes referred to as "Go Free"), which is connected to the boat network by Ethernet. The nav table Zeus plotter has a switch in it, to which the radar and the other plotter are connected, as well as the WiFi One.


The WiFi one is a wifi router. As long as I don't have any other network adapter on the boat computer connected to anything, the Ethernet connection works fine. The network identifies as "GoFree Wifi 21D2". I get radar as well as network data (in NMEA 0183 form), and I can control the radar from the boat computer using the OpenCPN Navico radar plug-in.


I could do as you suggest and connect the WiFi One to a Huawei router instead of to the boat computer, and plug the boat computer into the router. But this would require the router to be on -- and I don't need it offshore. Also it would be somewhat complicated to use a wifi Internet connection (rather than the mobile phone connection which the Huawei B593 makes itself).



I don't use Internet much on the boat computer because I don't do general computing on it, but I do need to connect from time to time to download GRIBs, update software, load charts, etc. I could just unplug the Ethernet cable whenever I do so, which is what I've been doing. But this network problem is a puzzle which I would like to solve just on principle!


I pulled up the routing table as you suggested. It looks like this:


Attachment 175169




So the idea is to create a Persistent Route to the Go Free router, which will be unaffected by other network connections?

Based on your screenshot, All of your network traffic currently goes to one interface.

You can add multiple routes by using Windows route command. You would need to do that every time you start the computer and most likely every time you power on the Huawei router. Windows tends to flush routes if the interface goes away.

The good news is that it is single command and it can be automated with a small script.

[Sailorboy FIN]

Originally Posted by Sailorboy FIN

Based on your screenshot, All of your network traffic currently goes to one interface.

You can add multiple routes by using Windows route command. You would need to do that every time you start the computer and most likely every time you power on the Huawei router. Windows tends to flush routes if the interface goes away.

The good news is that it is single command and it can be automated with a small script.

Just in case clarification is needed:
The network destination 0.0.0.0 is your default route. All traffic that is not specified in the routing table will go there and in your case the gateway out is 192.168.0.1.

What you want to do is to specify the default route to hit your Huawei router and add a special route to your GoFree network.

Make sure the IP addresses are not overlapping and that you use internal network range.

I would make the GoFree network to be 10.0.0.0 with a netmask of 255.255.255.0 and the Huawei network to be 192.168.0.0 with netmask of 255.255.255.0. That way the two would be easy to identify.

[Dockhead]

OK, thanks for all of this. Does it make sense to use one of these tools to manipulate the routing table?


https://www.raymond.cc/blog/choosing...le-editor-gui/

[Sailorboy FIN]

Originally Posted by Dockhead

OK, thanks for all of this. Does it make sense to use one of these tools to manipulate the routing table?


https://www.raymond.cc/blog/choosing...le-editor-gui/

You could pick the one you like. I’m more of a scripting kind a guy and would just write a script that would automatically do the right thing, every time.

[Dockhead]

Originally Posted by Sailorboy FIN

You could pick the one you like. I’m more of a scripting kind a guy and would just write a script that would automatically do the right thing, every time.

Your skills are above average, and certainly above mine


It's been about 25 years since I wrote a script for anything, and I'm not sure I'm willing to devote the time to get back up to speed.

[Sailorboy FIN]

Originally Posted by Dockhead

Your skills are above average, and certainly above mine


It's been about 25 years since I wrote a script for anything, and I'm not sure I'm willing to devote the time to get back up to speed.

I would not count on my skills, but I have time

In that case, NetRouteView seems to do the trick.