I have galaxy J7 and lineageOS 17.1. When I send a file with KDE connect from my phone to another device (another phone or a laptop) I am successfull, but in reverse not. For example when I try to send a file with KDE connect from my laptop to my phone a notification appears saying "failed receiving file from ...".

I have a rooted Pixel with Android 12. It is connected to a router to share the connection via tethering USB. Phone -- ISP IP = random -- tethering interface (rndis0) = IP random Router -- IP client random -- LAN IP 192.168.178.1 I would like my phone to reach my LAN. At the moment, pinging 192.168.178.1 from the phone doesn't work. Is it possible to do it without fixing the random IPs above?

When I boot up my Android Device and go to WiFi settings, the status of WiFi remains "Turning Wi-Fi on" forever. I looked it up in logcat logs, and below is the error that I see. E/wpa_supplicant( 1713): nl80211: Could not set interface 'wlan0' UP E/wpa_supplicant( 1713): wlan0: Failed to initialize driver interface E/wpa_supplicant( 1713): Could not read interface wlan0 flags: No such device Below is some useful information. root@android:/ # netcfg netcfg lo UP 127.0.0.1/8 0x00000049 00:00:00:00:00:00 gannet0 DOWN 0.0.0.0/0 0x00001082 1e:e9:6e:bf:45:f7 dummy0 DOWN 0.0.0.0/0 0x00000082 ba:ad:f6:ae:6a:09 rmnet0 DOWN 0.0.0.0/0 0x00000000 00:00:00:00:00:00 rmnet1 DOWN 0.0.0.0/0 0x00000000 00:00:00:00:00:00 rmnet2 DOWN 0.0.0.0/0 0x00000000 00:00:00:00:00:00 rmnet3 DOWN 0.0.0.0/0 0x00000000 00:00:00:00:00:00 rmnet4 DOWN 0.0.0.0/0 0x00000000 00:00:00:00:00:00 rmnet5 DOWN 0.0.0.0/0 0x00000000 00:00:00:00:00:00 rmnet6 DOWN 0.0.0.0/0 0x00000000 00:00:00:00:00:00 rmnet7 DOWN 0.0.0.0/0 0x00000001 00:00:00:00:00:00 sit0 DOWN 0.0.0.0/0 0x00000080 00:00:00:00:00:00 ip6tnl0 DOWN 0.0.0.0/0 0x00000080 00:00:00:00:00:00 Contents of /system/etc/wifi/wpa_supplicant.conf: update_config=1 ctrl_interface=wlan0 eapol_version=1 ap_scan=1 fast_reauth=1 **Question**: How can I enable Android to use some other interface other than wlan0? Things tried: 1) I tried to edit ctrl_interface parameter in /system/etc/wifi/wpa_supplicant.conf using adb pull and adb push to other interfaces shown by netcfg, but Android still tries to use wlan0. 2) I also tried to start wpa_supplicant daemon using the below command. /system/bin/wpa_supplicant -Dnl80211 -idummy0 -c/system/etc/wifi/wpa_supplicant.conf but this gives an error. E/wpa_supplicant( 5390): dummy0: Failed to initialize driver interface

The question says it all. I am learning my way around all the network connections my phone wants to establish. System is official /e/os on a Fairphone 5. Running adb shell netstat -eltup I get Active Internet connections (only servers) Proto Recv-Q Send-Q Local Address Foreign Address State User Inode PID/Program Name tcp 0 16 0.0.0.0:50057 0.0.0.0:* UNKNOWN radio 29453 1393/netmgrd tcp 0 16 0.0.0.0:50026 0.0.0.0:* UNKNOWN radio 30870 1393/netmgrd tcp 0 16 0.0.0.0:50058 0.0.0.0:* UNKNOWN radio 29468 1393/netmgrd tcp 0 16 0.0.0.0:50027 0.0.0.0:* UNKNOWN radio 30871 1393/netmgrd tcp 0 16 0.0.0.0:50059 0.0.0.0:* UNKNOWN radio 29469 1393/netmgrd tcp 0 16 0.0.0.0:50028 0.0.0.0:* UNKNOWN radio 30832 1393/netmgrd [...] udp 0 0 0.0.0.0:50043 0.0.0.0:* ESTABLISHED radio 29431 1393/netmgrd udp 0 0 0.0.0.0:50050 0.0.0.0:* ESTABLISHED radio 30838 1393/netmgrd udp 0 0 0.0.0.0:50051 0.0.0.0:* ESTABLISHED radio 30839 1393/netmgrd udp 0 0 0.0.0.0:50054 0.0.0.0:* ESTABLISHED radio 29454 1393/netmgrd udp 0 0 0.0.0.0:50055 0.0.0.0:* ESTABLISHED radio 29455 1393/netmgrd udp 0 0 0.0.0.0:50058 0.0.0.0:* ESTABLISHED radio 30880 1393/netmgrd udp 0 0 0.0.0.0:50059 0.0.0.0:* ESTABLISHED radio 30881 1393/netmgr` I just included a selection, the complete list is longer. Is this expected behavior?

If I am home, I am only using Wifi with 5G OFF. If I am out somewhere, work, etc. I use 5G with Wifi OFF. **The question: can I enable Wifi+5G always ON?** Thinking of security issues like: - if someone can break in to my phone via the internet/5G network, it can see my internal network (since Wifi is ON) - if Wifi is always enabled while I am outside home, can it be used maliciously? eg.: forcing my phone to connect to a fake wifi network?

I've installed [Neo Backup](https://f-droid.org/packages/com.machiav3lli.backup) which allows me to do (scheduled) backups of my applications data to device's file system. Now what I want is to use my PC as a storage for that backups, and transfer them via wifi. I have 2 Wi-Fi use cases: - When my phone and PC are connected to the home router, - And when my PC connected to the phone in hotspot mode. So I want backups to work in both cases. There are application named [SyncThing](https://syncthing.net) which I familiar with, but it's not suitable for my case because I don't want backups to be stored and take space on the phone at all. But one great feature of SyncThing is that both devices can find each other no matter which local network they are in. I tried [CIFS Documents Provider](https://f-droid.org/ru/packages/com.wa2c.android.cifsdocumentsprovider) , and it works, but only when I know exact IP or hostname of my PC in local network. It seems like what I really need is the similar application but with ability to find my PC no matter what IP or hostname it has. Anyone can suggest such, or maybe other solution for my needs?

I'm currently following a pentesting book by Georgia Weidman. I'm in the ARP spoofing part. I enabled IP forwarding using sysctl, and added MASQUERADE to the POSTROUTING chain in the NAT table. But when I set the filter in Wireshark to the incoming packets to the target's IP (ip.dst == target's ip), all I see are green ICMP network unreachable from my IP (attacker) and other DNS servers. The outgoing is fine, but mostly DNS. I also tried flushing the filter table and adding set iptables -P FORWARD ACCEPT. The target can't browse anything. I tried searching for ARP spoofing and MITM. I learned about MITM proxy and set up redirects from 80 and 443 to 8080. It works, but it's almost red, maybe because the target does not trust the MITM proxy, so I tried a regular proxy from the Play Store, and it works. The DNS is still green, but I will try to redirect 53 to 8080 later. Is this the only way to perform IP forwarding in Android? Additional Info: After everything, the packets in FORWARD chain from iptables -nvL is 0.

On my PC (Windows 11) I can simultaneously use zScaler and Tailscale. They work in different ways but ultimately they build micro-tunnels for specific destination IPs (using the IPv4 CGNAT or IPv6). I noticed that my phone (Samsung Galaxy 25+, Android 13) refuses to have both living together (it becomes a network mess). My question: Does Android support two or more simultaneous "VPN"s (the naming is not clear). Or in other words: can I have two small keys at the same time in the top bar (which would indicate two VPNs working simultaneously)? I am especially interested in the core availability ("are two possible at all") more than possible conflicts (which are a problem but may be fixable through configuration like in the case of default zScaler and Tailscale configurations)

I want to move the DHCP server from my OpenWRT router to the admin’s phone (with a static IP) because I need the network to handle 200 devices connecting and disconnecting quickly—about 30 seconds per device, with up to 200 devices in 5 minutes. The router gets very slow after 70 devices, so I developed a DHCP server app for Android. But I found out that it can’t listen on port 67 without root, and rooting all admin phones isn’t practical. I considered using an external device, but I’m worried about efficiency and debugging compared to using my own app. Is there a solution to run a DHCP server on Android without root, or another easy way to offload DHCP from the router while keeping flexibility and speed? The router specs are in the attached image. Image resized. Click to see the full size

I have installed "Termux" app on my Android device. I can this use this command on Termux app to create a Socks 5 tunnel to my remote VPS on port 1080:

ssh -D 1080 user@22.15x.20y.150

Then I use "Exclave" app to proxy my Android device through that port. But as soon as I activate the connection on Exclave app, the ssh connection on Termux app is terminated. Consequently the Exclave app cannot connect the Android device through the ssh tunnel to the Internet. I'm not sure, but it looks like a cycle problem or loop problem to me. So far, I couldn't find a way to modify Exclave app to exclude the ssh Socks 5 connection from the proxy. What are the solutions to this problem? I'm open to any solution that might possibly solve my original problem. Thanks.

My phone (Google Pixel 6 and Android 15) is connected to both 4G and a Wifi network with no Internet. The wifi network gives me IP address 192.168.4.2 and I know there's a WIFI Access point on 192.168.4.1. The 4G network gives me IP address 10.96.106.X. When I am connected to both networks I go to Termux and I try:

ping 192.168.4.1

but ping is unsuccessful - all the packets time out. Then I disconnect the 4G and I try again:

ping 192.168.4.1

and then the ping is successful. It seems like Android is thinking "The only way to perform the ping is go through the 4G network because your Wifi doesn't have internet", so it does the ping over the 4G network and hence it is unssuccesful. But that's wrong - I'm trying to ping an internal IP address on the wifi network so it should do the ping succesfully. Any suggestions? P.S. I can manually specify the interface like this:

ping -I wlan0 192.168.4.1

and then ping works fine, but unfortunately I'm building a flutter app and the APIs I am using does not allow specifying the interface name. To me it looks like a bug in Android.

I have a rooted device, and I want to use the internet via mobile data and let the LAN access via WiFi, but when the WiFi is connected, the gateway changes to WiFi. I have read similar answers like this which uses iptables, but I couldn’t get it working — likely due to my limited experience with iptables. Some suggested using AFWall+ and NetGuard, but that too didn't work. Now, I have managed to set up IPv4 access (i.e., I could access any IPv4 sites), and local access is also set, but only IPv6 is a problem now. I could ping IPv6 addresses, but for example, if I visit facebook.com, it wouldn't work. While modifying the hosts file to 2a03:2880:f184:186:face:b00c:0:25de www.facebook.com works, I need it to be done automatically by the default DNS server Would really appreciate it if someone could help me with it.

I wanted to use my Android phone as a proxy server, meaning that I wanted to be able to use the IP on the phone as a proxy, so all requests and responses are received on the phone and forwarded back to the original requestor. How do I do this?

When you connect to a WiFi network, the router assigns an IP to the android device (like 192.168.1.105). Now when a FTP or HTTP file server is run on the android device, other devices should type that IP to connect to the server. This IP is not fixed. When you switch to another WiFi network or enable hot-spot on android itself, it changes. Is there any way to assign a **fixed hostname** (for example my-pixel) so other devices could use it instead of the IP (like ftp://my-pixel.local:4030)? (I also asked this on Stack Overflow but no answer there)

I managed to run an Android emulator:

$ emulator Android30
INFO    | Storing crashdata in: /tmp/android-pcmagas/emu-crash-34.2.14.db, detection is enabled for process: 93905
INFO    | Android emulator version 34.2.14.0 (build_id 11834374) (CL:N/A)
ERROR   | No AVD specified. Use '@foo' or '-avd foo' to launch a virtual device named 'foo'
$ emulator -avd Android30

And I have a Realtek RTL8188EUS Wi-Fi USB dongle. How can I pass through it to the emulator so I can make the emulator manage it directly? I want to do similarly as I do with VirtualBox:

I want to create a network where my phone is the server, other phones can connect to my phone, and all of them can read or write on *a specific folder*, not all of my internal storage. Recently, I was trying to use SSH (using Termux). I searched and asked about it on [Server Fault](https://serverfault.com) . So, I could not find a way to use that. Is there any other way? I don't know if I can do this with SSH or any other protocol. (I use Termux, and if there is any way that needs Linux, I will thank you for sharing it with me.) I don't have a computer, so I prefer solutions without requiring it. I am ready to do it the hard way because it's the only possible way for me. Thank you. Edit: my phone is Xiaomi Redmi 10. 128GB with 4GB RAM.

I am testing IPv6 settings on my network and **during troubleshooting, I found that when using ULA address, ping to android device is failing. I am using Android 14. Is this expected behavior for Android or I might have some misconfiguration in my network?** I can still ping android device on IPv6 GUA (temporary + permanent RFC 7217) and ipv4. No issues there. In addition to that, Android device can reach local services on my network using ULA addresses

I live in the UK and recently I felt the need of getting a VPN. Everywhere. There is an option in Android 6.x: Always-on VPN, but there are two issues with it: - It does not reconnect after a lost connection. That usually means that whenever connection drops for some reason, you have to unlock the phone -> Go to Settings -> More connection settings -> VPN -> More -> Always-on VPN, change the server you like to connect to, click OK and wait ~5s for it to recconect. Why wouldn't it reconnect automatically (or maybe it doesn't do that only in certain situations)? - In case the server is not available, I would like to be able to establish more than one VPN service, so the phone tries the first one, if it can't connect, then go to the second one, then the third, etc. Is it possible?

I am running LineageOS 20 (Android 10) on my Xiaomi Redmi 9 (lancelot) rooted using Magisk. I started a WiFi-hotspot and based on https://android.stackexchange.com/a/213626/521733 , I used the following commands from a root shell:

lancelot:/ # ip a show ap0
35: ap0:  mtu 1500 qdisc mq state UP group default qlen 1000
    link/ether c2:98:90:46:b0:dc brd ff:ff:ff:ff:ff:ff
    inet 192.168.233.181/24 brd 192.168.233.255 scope global ap0
       valid_lft forever preferred_lft forever
    inet6 fe80::c098:90ff:fe46:b0dc/64 scope link 
       valid_lft forever preferred_lft forever
lancelot:/ # ip a add 192.168.100.1/24 dev ap0

Then, I connected to the hotspot using three methods: 1. DHCP Client received an IP: 192.168.233.81/24 Obviously, I was able to ping the Android gateway, as expected. 2. Static IP withing the 233 subnet Client IP: 192.168.233.10/24 Gateway and DNS: 192.168.233.81 Once again, I was able to ping the Android gateway, as expected. 3. Static IP within the 100 subnet Client IP: 192.168.100.10/24 Gateway and DNS: 192.168.100.1 **I was not able to ping the Android gateway.** There aren't any iptables rules that would drop this traffic:

lancelot:/ # iptables-save | grep tether                                                                                                                                
:tetherctrl_raw_PREROUTING - [0:0]
-A PREROUTING -j tetherctrl_raw_PREROUTING
-A tetherctrl_raw_PREROUTING -i ap0 -p tcp -m tcp --dport 21 -j CT --helper ftp
-A tetherctrl_raw_PREROUTING -i ap0 -p tcp -m tcp --dport 1723 -j CT --helper pptp
:tetherctrl_nat_POSTROUTING - [0:0]
-A POSTROUTING -j tetherctrl_nat_POSTROUTING
-A tetherctrl_nat_POSTROUTING -o wlan0 -j MASQUERADE
:tetherctrl_mangle_FORWARD - [0:0]
-A FORWARD -j tetherctrl_mangle_FORWARD
-A tetherctrl_mangle_FORWARD -p tcp -m tcp --tcp-flags SYN SYN -j TCPMSS --clamp-mss-to-pmtu
:tetherctrl_FORWARD - [0:0]
:tetherctrl_counters - [0:0]
-A FORWARD -j tetherctrl_FORWARD
-A tetherctrl_FORWARD -j bw_global_alert
-A tetherctrl_FORWARD -i wlan0 -o ap0 -m state --state RELATED,ESTABLISHED -g tetherctrl_counters
-A tetherctrl_FORWARD -i ap0 -o wlan0 -m state --state INVALID -j DROP
-A tetherctrl_FORWARD -i ap0 -o wlan0 -g tetherctrl_counters
-A tetherctrl_FORWARD -j DROP
-A tetherctrl_counters -i ap0 -o ccmni1 -j RETURN
-A tetherctrl_counters -i ccmni1 -o ap0 -j RETURN
-A tetherctrl_counters -i ap0 -o wlan0 -j RETURN
-A tetherctrl_counters -i wlan0 -o ap0 -j RETURN

Why is it not working? What is dropping the traffic? How do I fix it? My use case is as follows: I need to connect a Raspberry Pi to the hotspot and access it from my phone. Unfortunately Android hotspot subnet is set randomly, so I don't know the IP address that the client got assigned. mDNS does not seem to work, so the only other option I can think of is a static IP on a different, non-random subnet.

I have adb root at Android phone, that Android connect to internet using SIM card through rmnet_data0 interface How can I force change the IPv4 I get in rmnet_data0? When I down the interface and then upload the interface ,the IP stay same.