When Mobile Data and Wifi are Both Activated, Phone Cannot Connect to Internet
Context
- Device: OG PP
- Distros: Manjaro, postmarketOS
- DE: Plasma Mobile 5.25 (but also Phosh)
- KDE Gear: 22.06.
- Provider, Plan: T-Mobile USA; plan for talk and text only, no data.
When on Phosh, I am able to get MMS messages while connected to both LTE and wifi, but I cannot connect to the internet unless I disable mobile data.
On Plasma Mobile, I cannot download MMS while I am connected to both LTE and wifi. This problem should be corrected once !103 (merged) is merged for #30 (closed).
This is not a network priority issue; Manjaro has things properly prioritized for wifi over LTE.
This issue may be related: teams/plasma-mobile/issues#78
Problem
The issue I had on phosh still exists. If I am connected to both LTE and wifi, I cannot connect to the internet. I have to disable LTE before I can access the Internet (e.g., in terminal, in browser, etc.).
Diagnosis
I believe this issue is a DNS issue. When connected to both LTE and wifi, running ping
/mtr
commands shows that the only DNS recognized by the device is the LTE connection's DNS. This means that on this no data plan, the only recognized URLs are internal ones for the provider. Thus, even once !103 (merged) is merged, this problem (I would presume) should still exist.
Solution?
I believe what we would need to do is tell spacebar to use LTE DNS for MMS, but let everything else use wifi DNS.
We could run unbound in order to direct the DNS. If this is possible in systemd-resolve, I am not sure.