Describe the problem
I am trying to use NetBird on my Android phone. However, it seems to just sip mobile data all the time. Changing to “force relay”, turning on lazy connections in the dashboard or Rosenpass on/off doesn’t change anything. This makes it unusable for me, as it easily can just use 2-3GB a day just by having it be turned on, and on my plan I only have 20GB of mobile data each month. I have isolated this data usage to NetBird. I’ve never had this issue with Tailscale. I cannot test this out on another phone, unfortunately. Is this expected behavior?
To Reproduce
Be connected to NetBird via the Android client.
Expected behavior
NetBird should ideally not drain my data permanently, and especially not this amount of it.
Are you using NetBird Cloud?
I self-host the control plane.
NetBird version
v0.4.1
Is any other VPN software installed?
No
Have you tried these troubleshooting steps?
- Reviewed client troubleshooting (if applicable)
- Checked for newer NetBird versions
- Searched for similar issues on GitHub (including closed ones)
- Restarted the NetBird client
- Disabled other VPN software
- Checked firewall settings
So, by going through logs, I found that one particular node (NetBird on HomeAssistant) was kind of spamming requests at my phone but was then turned down by the ACLs. Maybe I don’t understand how the ACLs work, but there is nothing allowing HomeAssistant to connect to my phone, so I don’t understand, why it even tries?
This is what I used to find this issue (adb on Arch):
PID=$(adb shell pidof io.netbird.client)
adb logcat --pid=$PID
Dropping local packet (ACL denied): rule_id= proto=UDP src=100.80.215.142:48645 dst=100.80.91.150:<random_port>
I have restarted the HomeAssistant node and now the data usage has dropped significantly, to almost none. I don’t really know if this was the actual cause, or if there was another issue that was resolved by restarting, but hey, it helped me identify the problematic node!
Nope, there must be something entirely different going on; this was just one problem, it appears. I even completely removed NetBird from HomeAssistant, but all in all, NetBird on my Android still consumes from several hundred MB to up to 2 GB a day by itself. This happens with lazy connections and trying to have as few nodes that the phone can reach as possible. For my use case, this makes using NetBird completely impossible. Coming from Tailscale, which used a maximum of 200 MB at one point, I just can’t move on. Really love the project, though 
So if it’s not to much of an issue, could you try running a fresh netbird instance. Either on Cloud or by creating a temporary selfhosted instance. Then slowly add each machine back to your stack and see if there’s any device causing the data issue? The only thing I can imagine it being an issue is if the control plane has to constantly update something, and I would assume that is only the case if something changed.
Hey! Thanks for looking into it. Unfortunately I have already moved on and replicating the setup would take quite the effort. I don’t really have the time for that at the moment, sorry. All I might still be able to produce are the NetBird and JetBird client logs from the phone (I tried the alternative, in case it was the app). Would that still be of help? Don’t wanna waste your time as well, since I have found a setup I am pretty happy with now and wouldn’t really wanna change it. But if you want to look into it, I am happy do whatever I can to help!
No worries, maybe next time. The app still is getting updates, so who knows.