Ok, so maybe I'm just a lil paranoid lately, but I'm trying to block any - and ALL - connections to my phone. PERIOD. I have the paid version of Android Firewall.

If I select Black list from the drop down box and check WiFi, Data, Roam, VPN, LAN, & Input Chain for (Any Application) will that accomplish the goal I'm getting at?

  • 2
    Sure you didn't confuse the Android firewall concept with the "classical one"? On Android, firewall apps rather care for outgoing connections, as incoming connections usually are already "blocked" by the carriers. Even IMAP IDLE requires the client to establish the connection first, and I'm pretty sure the same is valid for C2DM. Though, as a side-effect it might work, depending on how the firewall app implements its firewalling.
    – Izzy
    May 30, 2014 at 21:47

3 Answers 3


I don't know how Android Firewall app worked, but it's simple to achieve with iptables; thanks to Linux kernel. Since Android uses default policy ACCEPT, drop any unwanted packets:

~# iptables -I INPUT ! -i lo -m conntrack ! --ctstate ESTABLISHED,RELATED -j DROP
~# iptables -I FORWARD -j DROP

This will also block incoming connections from tethered devices on hotspot network. You can exclude those, see this: Is There A Mobile Hotspot App With A Firewall to Block Incoming Connections?


Also you can put your phone in airplane mode. you will still be able to access wifi, but all other connections will be terminated. Just leave wifi off and your good to go.

  • uhhhm, no... Airplane mode kills wifi too. And I'm not sure how "just leaving wifi off" makes you "good to go". (But maybe he knows that, and that's why he hasn't returned since answering this.)
    – ashleedawg
    Feb 18, 2020 at 17:29
  1. All Android Firewall apps BLOCK ALL Outgoing data automatically when the app is enabled as a default action. The Firewall DOES NOT disrupt or block any incoming data into your device. ONLY outgoing data are Blocked. Basically, no data leaves your device when the Firewall is enabled; the Firewall app then informs you what app tried to connect outbound. It is then up to you if you will ALLOW such a connection the next time, OR choose to RESET the connection then ALLOW. OR BLOCK the outbound data connection wherein the DATA sent by the app will be dropped by the VPN sinkhole (for NoRoot Firewall apps), thus fooling the app who attempted for an outbound connection that the data was "sent".

  2. You can use Airplane Mode to Block All IN/OUT connections, and isolate your device from all radio traffic. Though each type of phone or device, brand, version of Android, have different ways to achieve True Airplane Mode action. You can enable Airplane Mode, take out batteries (believe you me) usually gives you true isolation. But when the battery is integrated on the device then it's a bit tricky; You should then first go to SETTINGS/WIRELESS NETWORKS/SIM CARDS and Deactivate the SIM Card or Cards if there are two; THEN proceed to Enable Airplane Mode for better isolation.

*you can try to scan your area with your device using another android device by using Bluetooth Firewall app and check. In my case, my Lenovo Tab3 730 was picked up by an Android phone running BTFW app even when Airplane Mode was Enabled !!!

So there has to be a TRUE Airplane Mode state for each and every Android device.

  1. You can download compatible apps that will lockdown WiFi, and Bluetooth to secure any attempt by the Android device to try to connect by other ways because in the Android system, when you disable Mobile Data Connection, WiFi /Bluetooth will AutoStart.

Such apps include Device Control by Expert Systems Co. and D-Vasive app by D-Vasive Inc. In my opinion, these apps WITH the Airplane Mode coupled as above, might be overkill, but I presented the answer, hopefully on the level of your concern reading your question, if not the size of the TinFoilHats we are wearing? 😁


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