Possible Network Routes Conflict

[werlitong]

Describe the problem Seems to be a routing conflict that cause network issues. I was testing netbird and saw that after add a route to 192.168.1.0/24 i've lost access to all my internal network, only gateway (my ubiquiti's router) is accessible. So, i changed from my WiFi to 5G/4G and i surprisingly recover the access. The problem wont occour if i change the route to target a specific resource in my network or if i just disable the route in netbird dashboard.

To Reproduce Steps to reproduce the behavior:

1. Create a network route for all of your internal network subnet (masquerade enable and metric set to 9999)
2. Try to access any resource excluding the gateway.

Expected behavior I think that the expected behavior should be routes beeing created following a priority distance. I'm not sure.

Screenshots Screenshots of command netstat -rn Route to 192.168.1.0/24:

Route to 192.168.1.240/32:

[mlsmaycon]

Hello @werlitong, can you confirm that your computer's local network is 192.168.1.0/24? I am not seeing the local reference for it pointing to your local network interface:

e.g., at my place, the network is 192.168.178.0/24:

The NetBird agent looks for this network when adding the configured route in your system's routing table. So if it is missing, that check won't find it and will think it is ok to add the incoming route.

[werlitong]

Yes, subnet its correct. Maybe that's the point, check the first screenshot (first post), seems like netbird replace de route from my system if there is a route to the hole subnet /24. In other words if i put my home subnet in netbird and try to access a resource with netbird up and running using my local wifi it will cause the issue.

1.Running the command with netbird disabled:

2.Running the command with netbird route to a specific host in the network:

3.Running the command with netbird route to the hole subnet /24:

[mlsmaycon]

Thanks, @werlitong. We will investigate more as I cannot reproduce the case locally.

[werlitong]

Sure thing! If there's any other test, i'll be happy to help! Thanks!!

[mlsmaycon]

Actually, it would be great if you could create a route like this:

sudo route add 8.8.0.0/16 192.168.1.1

And then do the same checks again you did with your local net.

[werlitong]

Here it is:

[werlitong]

@mlsmaycon just test the new version 0.25.4 and problem seems to be fixed. Thank you!

[werlitong]

i've just saw that problem still occur, i thought that was solved but recently experienced the issue again.

[fti7]

I have the same issue on a Windows Client. Netbird 0.26.2. Windows 10

On a freshly booted System (Route disabled in Netbird) i have an local route to my local Subnet.

When i enable the Route in Netbird. Nothing changes (Good, because local route already exists)

When i disable it again. Netbird delete the complete local route (Is there a Check Missing to only remove Routes with a Netbird GW?) When i enable it again. It adds a new Route with a Netbird Peer -> All Hosts in my Subnet are unreachable

[guiguan]

same here. Netbird will remove the local route with matching CIDR, and re-add Netbird one when reconnecting. This makes the local route unusable. Please only remove the route with Netbird gateway

[fti7]

@mlsmaycon any update on this? can you reproduce this now? thanks

[mlsmaycon]

Hello, folks; we will work on this in the coming weeks. It should be in 0.28.0

[fti7]

Hello, folks; we will work on this in the coming weeks. It should be in 0.28.0

any update on this? is it already fixed?

[captainnx]

it not fix now