Network Response Time Out Error (create-react-native-app) (expo)

Question

I am trying to run create-react-native-app on expo app in android.

Firstly ,I created the project by writing command

create-react-native-app test

then I executed

npm start

then scanned the qr code from expo app.

But after scanning QR code , I am getting following error:

Uncaught Error: Java.net,sockettimeoutException: failed to connect to after 10000ms

Github Issue:

https://github.com/react-community/create-react-native-app/issues/144#issuecomment-296631692

Answer 1

This is due to not open port from your machine.

Linux (Ubuntu)

In Ubuntu Run In terminal

sudo ufw status verbose To view open port if you cannot found 19000 port open then you need to open port using

sudo ufw allow 19000/tcp

and then again run

sudo ufw allow 19001/tcp

to serve http for react native i solve this problem in my ubuntu using this method. I hope this will help you.

Windows

To open a port in the Windows firewall for TCP access On the Start menu, click Run, type WF.msc, and then click OK.

In the Windows Firewall with Advanced Security, in the left pane, right-click Inbound Rules, and then click New Rule in the action pane.

In the Rule Type dialog box, select Port, and then click Next.

In the Protocol and Ports dialog box, select TCP. Select Specific local ports, and then type the port number of the instance of the React port, such as 19000 for the default instance. Click Next.

In the Action dialog box, select Allow the connection, and then click Next.

In the Profile dialog box, select any profiles that describe the computer connection environment when you want to connect to the Database Engine, and then click Next.

In the Name dialog box, type a name and description for this rule, and then click Finish.

Similarly you can open port 19001 too.

Answer 2

Change connection from LAN to tunnel.

Answer 3

In my case the firewall settings alone didn't do it. My issue was that VirtualBox network devices were taking priority and the Expo host was starting on the wrong network.

On windows you can run ipconfig and look at the network adapters you have. npm/yarn start seems to take whatever shows up first in that list.

I found out about this from here: https://github.com/react-community/create-react-native-app/issues/60

If you don't need the other network adapters in the list, you can disable them in the Network Connections interface of the Control Panel.

If you need to use those connections and have Expo work then to solve the issue I followed this process:

1. Goto Control Panel > Network and Internet > Network Connections
2. Right click the desired connection (Higher Priority Connection)
3. Click Properties > Internet Protocol Version 4
4. Click Properties > Advanced
5. Uncheck 'Automatic Metric'
6. Enter 10 in 'Interface Metric'
7. Click OK

Repeat for the Lower Priority Connection, but this time put 20 into the 'Interface Metric'

You'll now use the higher priority connection as a default.

Answer 4

You can get around that by fixing your laptop's ip address to a static ip, let's say 192.168.1.69, then you need to change the react native packager ip address to the same of your laptop, using

set REACT_NATIVE_PACKAGER_HOSTNAME=192.168.1.69 (Windows)
REACT_NATIVE_PACKAGER_HOSTNAME=192.168.1.69 (Mac & Linux)

start your project again and you're good to go.

Answer 5

I had done everything mentioned in context. Just Changed my connected WiFi network from public to private. This Worked for me

Answer 6

First of all, disable the unused network connection. In my case it was VirtualBox. Maybe it's using the same port. I am not sure about that. after disabling the unused connections then restart the packager. if you used npm then type

npm start

Answer 7

• Found ipv4 address
• open expo app then tap to explore button from bottom
• write exp://[ipv4adress]:19000 to searchbar
• Then your app will open

Answer 8

change LAN to Tunnel to solve this issue

Answer 9

I suggest you install expo application for react native, link to official guide here

npm install -g exp

Then you can use Genymotion software to emulate different environment setting for your app an run:

exp start

If you use in the terminal "npm start" with native react, the following is for you. I found out that if my application runs successfully IpV addresses of my computer, that are shown in the terminal and that is on Expo app are identical, for example:

ipconfig -> IPv4 Address. . . . . . . . . . . : 10.0.0.124
exp://10.0.0.124:19000

Based on this observation I solved this issue by the following way:

1. Close npm prompt script which is running app
2. Close Expo app

3. Find your IP by running command in the terminal:

   ipconfig
   

4. Run command in NodeJS command prompt with your IP (for example 10.0.0.124)

   set REACT_NATIVE_PACKAGER_HOSTNAME=10.0.0.124
   

5. Start Expo app, scan barcode

   npm start
   

   If it does not help, then use next steps recommended by React developers in addition to other reasonable efforts:

6. Install Genymotion with VirtualBox
7. SignUp at Genymotion site
8. Run Genymotion software and !!!SignIn

Answer 10

If you are using git bash for development then this solution by Icruz4 will help

Instead of

set REACT_NATIVE_PACKAGER_HOSTNAME

Use:

export REACT_NATIVE_PACKAGER_HOSTNAME='192.168.1.123'

Note:

When you run

npm start

Expo tells you in the output the IP it's using. If that IP is not the IP you want then the

REACT_NATIVE_PACKAGER_HOSTNAME

environment variable is not set properly

Answer 11

in Windows

1. run the ipconfig in command prompt

2. get the ip4 address and copy it.

Than go to

1. This PC > properties > advanced system settings > environment variables
2. add the following system variable: REACT_NATIVE_PACKAGER_HOSTNAME
3. As the value for the variable I had to paste the ip4.

then run the npm start It's work for me

Answer 12

I've had the same issue. The problem is that the command yarn start or npm start finds the first enabled network adapter it finds which just happens to be the adapter for VirtualBox on my (and many other machines). The solution is to either:

manually set REACT_NATIVE_PACKAGER_HOSTNAME environment variable, or disable the unused network adapter in Windows' Network Connection (see image) The problem is that Expo finds the first Network adapter, and not the active network adapter that provides the internet connection.

Answer 13

In case someone is still looking for the answer. Do the basic thing first, Disable the VirtualBox Host-Only Network first by opening your network configs. This worked for me.

Answer 14

If you have tried everything the other answers suggest and it still does not work, please also check that your computer and your phone are connected to the same WIFI network. For me this is what wasted an hour.

Answer 15

Solution 1:- Connect both(your PC and mobile)with same network then scan the QR with expo application.

Solution 2:-Select / change connection type as Tunnel mention in local host development window of your browser then scan the QR with expo application.

I think this will help :)

Answer 16

My problem is solved by navigating to my project folder and running the below commands:

expo start --tunnel

then start android app by typing

a

Answer 17

This issue could possibly be resolved by:

Setting your environment variable with alternative instructions here

Or

Assigning interface matrix priority for your network adapters with detailed instructions here or here.

Or

An Ubuntu machine is unable to open a port

After you make any changes, please restart the computer before testing if it works.

Good luck!

Answer 18

I tried many solutions, only this way helped me to solve this problem:

In Windows:

• go to "Network and Connections" in Control Panel of windows (Network and Sharing Center>Change Adapter Setting)
• Disable all virtual boxes which you can see here
• Restart npm or yarn or expo...

Answer 19

In my case, this problem occurred because Expo android app need "draw over other apps" permission and I didn't give it. So I give this permission to Expo app and the problem solved..

Answer 20

One of the simplest and 100% working solutions is:

1. Enable the Mobile Hotspot of your development machine( PC or Desktop ) and connect your Android device with this hotspot.
2. Goto Control Panel > Network and Internet > Network Connections You will land in here as shown:Network Connections setting
3. Then set the IP address of Local Area Connection(Your DESKTOP HOTSPOT) to a desired one, say: 192.168.1.69 by right-clicking on the concerned connection and then clicking on properties -> Internet Protocol Version 4(TCP/IPv4) -> Properties. Then set the priority of this connection to be the highest and this is best described here

4. Then open a command terminal and run:

   set REACT_NATIVE_PACKAGER_HOSTNAME=192.168.1.69 (Windows)
   REACT_NATIVE_PACKAGER_HOSTNAME=192.168.1.69 (Mac & Linux)
   

5. Then restart your expo server by running npm start in your expo project folder and run the app on your Android device by scanning the generated QR code with the expo app.

Answer 21

This error beaus your port it is not open just check port is open or not for ubuntu you can check using the following way

sudo ufw status verbose

check 19000 port open then you need it then run following command if port not open

 sudo ufw allow 19000/tcp

for other port runs following command

sudo ufw allow 19001/tcp

because http port not you are getting erro. above step solve your problem similar for mac and windows check firewall setting once

Answer 22

I had the same issue after npm start script on windows environment. Putting mobile on the same network as my Windows development environment was solved issue.

Answer 23

I had the same issue I got this when I cancel the permission window of node js I solved it by going at the directory

1. On the Start menu, click Run, type WF.msc, and then click OK.
2. In the Windows Firewall and Advanced Security, in the left panel in Inbound Rules I had two options or rules disabled Node.js Serverside Javascript.

I simply double click and in new window In action, I select allow the connection and save

Answer 24

Starting EXPO using the -- tunnel flag should help: $ expo start --tunnel

Answer 25

I had the same issue but after some research, I found that this is because your computer has previously connected to multiple adapters. Expo may pick the IP address of one of these. To avoid this

1. Go to the command prompt and write 'ipconfig'.

2. Copy the IPv4 Address under Wireless LAN adapter Wi-Fi.

3. Then wrte the below command.

set REACT_NATIVE_PACKAGER_HOSTNAME=(Your IP here)

Answer 26

i just want to remember this for those who only try to scan the QR Code

You need to connect your phone to your computer using a USB cable the first time you want to launch the app,that will install the app on your device then the expo scan will work, i think all the solution above will work maybe it's just because you didn't connect them first that everything didn't work

just read the docs https://reactnative.dev/docs/running-on-device

Answer 27

I got it by using this command on my ubuntu system:

sudo ufw allow 19000/tcp

and then type this:

sudo ufw allow 19001/tcp

restart vscode and the expo server and then you are good to go!

Answer 28

For Linux Ubuntu 21.10

This is for users, that don't use UFW.

Make sure ufw is inactive, else, execute 'sudo ufw allow 19000'

sudo ufw status

List rules:

sudo iptables -L

This will output on clean Ubuntu like this:

Chain INPUT (policy ACCEPT)
target     prot opt source               destination         

Chain FORWARD (policy ACCEPT)
target     prot opt source               destination         

Chain OUTPUT (policy ACCEPT)
target     prot opt source               destination  

Now allow port 19000 with command:

sudo iptables -A INPUT -p tcp --dport 19000 -j ACCEPT

Make sure that rule added:

sudo iptables -L

Expected output:

Chain INPUT (policy ACCEPT)
target     prot opt source               destination         
ACCEPT     tcp  --  anywhere             anywhere             tcp dpt:19000

Chain FORWARD (policy ACCEPT)
target     prot opt source               destination         

Chain OUTPUT (policy ACCEPT)
target     prot opt source               destination

After restart all rules will be wiped, so we need to install package, that will add rules from a file rules.v4 on each OS boot

sudo apt install iptables-persistent
su root
iptables-save > /etc/iptables/rules.v4

Enjoy! :)

Answer 29

If you are on Mac OS, this fixed it for me:

System Preferences > Network > Wifi

Uncheck "Limit IP Address Tracking".

This might have to do with iCloud Private Relay blocking your Mac from being seen by other devices.

Answer 30

In Windows,

set REACT_NATIVE_PACKAGER_HOSTNAME=my-ip-address

worked inside my git bash terminal, but not cmd. In git bash, after I ran npm start, I got a firewall popup, which I clicked allow and it worked!