How do I create a WiFi hotspot sharing wireless internet connection (single adapter)?

Question

I know how to create a hotspot when connected to a wired network, but when I am using internet from a WiFi connection, this disconnects the wireless connection the moment I activate the hotspot.

In Windows I can use Connectify Hotspot, which enables me to share the internet connection from the same wireless adapter as I am creating an access point on. As you can read on the technology overview page:

Access Point mode allows you to create a hotspot using the same Wi-Fi card that you are using to access the Internet.

How do I do this on Ubuntu?

Do you have two Wifi-Sticks or built-in-wifi? Because you need always one to receive and one to send. Even with connectify I think. If you look on their website they alsways show how to share 3G/4G via wifi, but never two wifi like they say in their advertisments. It IS possible, but only with two wifi adapters. I have never heard of a software technology that avoids that. There are other possibilities, though. — verpfeilt, Jul 11 '13 at 15:53
I've voted to reopen this question, because it is different from the "How to Share your Internet Connection" question. First of all, the OP found that option already (so does not need the answers there) and secondly, it is about the situation to use a single networking device to share the connection from and to. See also Hotspot and Internet access together — why not? — gertvdijk, Jul 25 '13 at 18:07
Very Interesting. I like to add, that from the hardware site of things, you need a capable Wireless Card (I know that the lenovo in office is not able to create wireless AP's, it's simply not possible by hardware, business security means) Another thing, is, that you need at least two Antennas to really make it work, or a magic software that can emulate two connections on one Antenna. P.S.: I am not a hardware technician. It is possible that I understood nothing and talk rubbish. ;) — mondjunge, Jul 26 '13 at 08:59
@mondjunge The single antenna will only force you to use the same frequency/channel. But yes, of course this could be disabled in hardware completely. However, most chipsets are universal by hardware. It's just firmware + drivers that make the difference for most. — gertvdijk, Jul 26 '13 at 10:10

Purushoth · Answer 1 · 2017-10-23T07:39:24.893

75

Simple steps: Create wifi hotspot in ubuntu

Disable Wifi (Uncheck Enable Wi-Fi)
Go to network connection (Edit Connections...)
Click "Add"
Choose "Wi-Fi" and click "Create"
Type in Connection name like "wifi-hotspot"
Type in SSID as you wish
Choose Device MAC Address from the dropdown (wlan0)
Wifi Security select "WPA & WPA2 Personal" and set a password.
Go to IPv4 Settings tab, from Method drop-down box select Shared to other computers.
Then save and close.
Open Terminal (Ctrl+Alt+T) and type in the following command with your connection name used in step 5.
```
sudo gedit /etc/NetworkManager/system-connections/wifi-hotspot
```
Find mode=infrastructure and change it to mode=ap
Now check the network section where wi-fi will be connected to the created hotspot automatically. If you can not find it, go to Connect to Hidden Network... Find the connection and connect to it.

Source: http://ubuntuhandbook.org/index.php/2014/09/3-ways-create-wifi-hotspot-ubuntu/

edited Oct 23 '17 at 07:39

answered Apr 14 '15 at 14:31

Purushoth

919

13

Simple, but doesn't answer seem to answer the question asked here: in my hands it does not result in sharing of wireless-to-wireless using a single wireless network interface. – Alex Coventry Jan 10 '16 at 00:08
4
a) Enable Wifi (Check Enable Wi-Fi)

Jess Telford

Aug 01 '17 at 02:33

My wifi-hotspot was created successfully but when I was connect my phone It Connected but no Internet access So How can I access my Internet access Plz help – Gagan Aug 10 '17 at 13:00

Using a USB WiFi adapter as the hotspot, so that my internal card can be the receiver of internet, I get this error: Connection failure. Failed to activate connection. (32) Access Point (AP) mode is not supported by this device. Any way to fix this? – Gabriel Staples Dec 15 '17 at 19:16

Great answer!...but....I couldn't get it to work--not on my external USB WiFi adapter nor on my internal Wi-Fi card as the hotspot. :( Here's my answer I just wrote that worked for me instead: https://askubuntu.com/a/986714/327339. – Gabriel Staples Dec 16 '17 at 02:30

2

Awesome :D, Step 14 -> Connect your laptop to lan and use it on mobile via the created hotspot. Super Awesome :D – Satys Dec 30 '17 at 06:17

2

Enable wifi, 15. in terminal ctrl+alt+t sudo service network-manager restart

– Ferroao Jan 17 '18 at 15:21

score 60 · Answer 2 · edited Apr 05 '19 at 07:58

After I saw this link offered by vasishath, I managed to setup a wireless hotspot to share the internet connection from the same single wireless interface device. This wireless device must to use an Atheros driver that is already build with nl80211 support. Next I will show you how.

Detect if your wireless device will work with this method

Run the following command in terminal:

lsmod | grep ath

If the output is null or if the string cfg80211 is not in the output, it makes no sense to continue and you should pay attention at second and third point from this answer.

Tools needed

Check whether all the below mentioned packages are installed: iw, hostapd, iptables, udhcpd, udhcpc, macchanger.

You can install these with

sudo apt-get install iw hostapd iptables udhcpd udhcpc macchanger

Edit some files

Run the following command in terminal to edit corresponding files:

sudo -H gedit /etc/hostapd.conf /etc/udhcpd.conf /etc/default/udhcpd /etc/wpa_supplicant.conf

In hostapd.conf file add the following code:

interface=new1
driver=nl80211
ssid=my_wifi_hotspot      #Change the ssid name as you wish
channel=11                #I sugest you to use the same channel as your wireless network
hw_mode=g
wme_enabled=1
macaddr_acl=0
auth_algs=1
ignore_broadcast_ssid=0
wpa=3
wpa_passphrase=1234567890 #Change the passphrase as you wish
wpa_key_mgmt=WPA-PSK
wpa_pairwise=TKIP
rsn_pairwise=CCMP

In udhcpd.conf file comment all the current lines (by adding a # character in front of the line) and add the following new lines:

start 192.168.0.102         #These IPs must to be in the same subset as your current default route
end 192.168.0.117 
interface new1 

opt dns 192.168.0.1         #Your current default route (Gateway)
option subnet 255.255.255.0
opt router 192.168.0.101    #This IP must to be in the same subset as your current default route
option  domain  localhost

In /etc/default/udhcp, comment the line that says DHCPD_ENABLED="no".
In wpa_supplicant.conf you must provide the settings of your current wireless network. See man wpa_supplicant for some quick examples. And you probably have more examples in /usr/share/doc/wpa_supplicant/ directory. I used something like:
```
ctrl_interface=/var/run/wpa_supplicant
network={
  ssid="my_wifi_network"
  key_mgmt=WPA-PSK
  proto=WPA
  pairwise=CCMP
  group=CCMP
  psk="mypassphrase"
}
```
Save all the files and close them.

Note: All of these edits doesn't affect with nothing your current network configuration.

Make a shell script

In a terminal run mkdir -p bin - this command will make a bin directory in your home folder if you don't already have it.
After run gedit ~/bin/hotspotsetup.sh - this will create the new file hotspotsetup.sh in gedit.
Copy and paste the following script in the new created file:

#!/bin/bash

service network-manager stop
sleep 1

pkill -15 nm-applet
sleep 1

ifconfig wlan0 down             #wlan0 - the name of your wireless adapter
sleep 1

iw phy phy0 interface add new0 type station
iw phy phy0 interface add new1 type __ap
sleep 2

ifconfig new0 down
macchanger --mac 00:11:22:33:44:55 new0
ifconfig new1 down
macchanger --mac 00:11:22:33:44:66 new1
ifconfig new0 up
ifconfig new1 up

ifconfig new1 192.168.0.101 up  #192.168.0.101 - the same IP defined for router in 'udhcpd.conf' file 
hostapd /etc/hostapd.conf &
sleep 2

service udhcpd start

wpa_supplicant -inew0 -c/etc/wpa_supplicant.conf &
sleep 10

udhcpc -i new0

echo "1" > /proc/sys/net/ipv4/ip_forward
iptables --table nat --append POSTROUTING --out-interface new0 -j MASQUERADE
iptables --append FORWARD --in-interface new1 -j ACCEPT

Save the file and close it.
Go back into terminal and run: chmod +x ~/bin/hotspotsetup.sh - to grant execute access for the script.

Start the wireless hotspot being connected to a wireless network from the same wireless adapter

Run the above script in terminal with root privileges:

sudo ~/bin/hotspotsetup.sh

Proof

hotspotsetup.sh

Note: To start again your network-manager service as it was before to run the hotspotsetup.sh script, restart your computer (sudo reboot).

Source: Connectify for Linux with Single wireless interface.

It is out of the question if this is possible by hardware or not. If a Windows and FreeBSD application/driver can do this, then it should be possible in Ubuntu as well. Maybe not through the usual NetworkManager way, but that's not a criteria for a valid answer. — gertvdijk, Jul 26 '13 at 10:07
Windows and free version of Connectify definitely can use same wifi card for both receiving and sharing internet connection, I use this feature alot and its the only thing I miss from Windows. I'm sure this is doable in Ubuntu as well if somebody create an open source driver with same feature as Connectify. — Nur, Jul 28 '13 at 07:59
@Nur There is a limited list of devices that have been tested by Connectify, or reported by multiple users, as fully-functional with Connectify Hotspot. So, not all devices will work in this sense — Radu Rădeanu, Jul 28 '13 at 12:27
I'm pretty sure my atheros card is fully functional because I already use connectify for ages, not a single problem happen. Gonna try this setup, I hope this'll work. — Nur, Jul 28 '13 at 17:44
This is a great answer, but I am having trouble getting it to work! I had to enable udhcpd in /etc/default/udhcp.conf, but still no luck. It keeps giving me Sending discover... and new0: CTRL-EVENT-SCAN-STARTED even though everything else went well... Also when I try to connect to the network it never works! I have edited your anser with regard to udhcpd, but can you please say how to fix the connection issue? — Richard, Jan 03 '15 at 07:15
Why do you have to use mac changer and why on both devices (physical and virtual)? — JSON, Feb 25 '16 at 01:27
How can you check if #This IP must to be in the same subset as your current default route? — Mark Deven, May 09 '19 at 19:19

kcdtv · Answer 3 · 2021-03-08T15:35:17.157

37

Let me introduce you to an excellent tool that simplifys everything: create_ap (by oblique)
That is the official repository: https://github.com/oblique/create_ap
This tool is part of Arch Linux repositories and should be in Ubuntu repositories too!
It is very easy to use and very effective.
To install it in Ubuntu you must first install the dependencies:

sudo apt install bash util-linux procps hostapd iproute2 iw wireless-tools haveged iptables dnsmasq git

Unless you used a "mini install image" you already have 90% of them...
Once it is done, clone the repository from oblique:

git clone https://github.com/oblique/create_ap.git

Locate your terminal in the downloaded repository:

cd create_ap

Install the tool with:

sudo make install

(no compilation with make is needed)
Easy, right? Well the rest is even easier... ...If your device is able to be used as a client and a PA at the same time (like atheros wifi chip - edit: some Intel chip too, see second comment bellow) you simply have to connect to your home router with network manager, as you usually do, and than you execute a command line like that:

sudo create_ap <connected interface> <repeater interface> <essid repeated network> <WPA Key>

example

sudo create_ap wlp2s0 wlp2s0 Bathroom_WiFi mysecuresecretkey

And... That's it! Incredible and so easy! Now you just have to connect to the repeated network with your android device. You will see in your laptop terminal the handshake negotiated between your laptop and the client: And you can enjoy a nice bathroom session with internet... Everything is done with a single interface and with one simple command. The tool have a lot of options, for more information visit the github repository of oblique (link given previously) and if you can speak Spanish you can check this forum thread: create_ap: La solución perfecta para transformar tu ordenador en un repetidor universal todo terreno

edit Oblique stopped the project

This project is no longer maintained.

The beauty of free code is that good projects never die and there are 2 github repositories that keep on Oblique good work:

edited Mar 08 '21 at 15:35

answered Aug 03 '18 at 13:26

kcdtv

2,325
3
16
22

3

Very impressive tool! – George Udosen Feb 02 '19 at 18:31
1

wow, it works. I have Intel Corporation Wireless 3160 and it works. I'm connected to wifi and have created ap on same adapter :D thx. – QkiZ Feb 12 '19 at 19:52
Thanks for your feedback! I will modify the mention that some intel chipset can act as universal wifi repeater too... Awesome. – kcdtv Feb 15 '19 at 17:56
I should learn to go through all the comments before attempting anything, wasted a lot of time with the other methods. This was the easiest and only one that works. Thanks. – vikki Apr 19 '19 at 00:21
Very easy and worked like a charm – Talha Junaid Apr 30 '19 at 12:16
What are the <connected interface> <repeater interface>s? – Mark Deven May 09 '19 at 19:21
5

Important instructions for devices that do not support AP and client at the same time, in your downloaded repo edit the file 'create_ap', 1. find and comment the line "CHANNEL=$WIFI_IFACE_CHANNEL" 2. find the function "is_wifi_connected()" and comment all inside it except for the last line "return 1" then run "sudo make install". This made it work for me ubuntu 18.04 on GPD Pocket 2. (would be great if you incorporate this in your answer) – Sruli Jun 07 '19 at 10:24
3

forgot to mention in my last comment that the instructions provided I took from https://github.com/oblique/create_ap/issues/107 – Sruli Jun 07 '19 at 10:30
@MarkDeven the depends on your hardware, if you only have 1 wifi interface then both would be the same for example if the wifi interface is "wlp3s0" and you want to name it "MyHotspot" with a password the command would be "sudo create_ap wlp3s0 wlp3s0 MyHotspot password" – Sruli Jun 07 '19 at 14:17
Works flawlessly (with the edits mentioned by Sruli and in the github issue). – Wang Tang Jul 13 '19 at 13:40
How can I make a systemd service work ? there is nothing in the log file create_ap errors if I try to use systemctl start create_ap – Ciasto piekarz Apr 16 '20 at 20:01
Notice that the repository is no longer maintained.. :/ – Jeppe Mar 05 '21 at 14:05
Thanks Jeppe for pointing that out, i edited the post. – kcdtv Mar 08 '21 at 15:36

Lakindu Akash · Answer 4 · 2021-10-07T09:24:59.460

23

Here is my project Linux Wifi Hotspot which has both GUI and command-line interface. It can create a virtual wifi hotspot on the same wifi adapter which is connected to the internet. It has additional features such as MAC filter, Change channel/frequency band, view connected devices etc.

edited Oct 07 '21 at 09:24

answered Nov 04 '20 at 22:25

Lakindu Akash

1,421

5

This is the least hassle option. Install & go. Works on my 7 year old HP Folio 1040 laptop with Intel Wireless 7260 on Ubuntu 20 LTS. Linux WiFi Hotspot simultaneously connects and distributes internet connection just with single NIC. You saved my day! – igor Dec 13 '21 at 09:49
1

This worked well on Arch Linux, and it works just as well on Lubuntu. Thanks for creating this project! – Logan Jun 02 '22 at 17:15
1

Works well on ubuntu 20.04 I've run it as root from console, also it let me use VPN (tun0) interface for AP... – Aleksandar Pavić Nov 29 '22 at 09:58
1

Excellent tool. Worked on Lubuntu – Ramin Arabbagheri May 19 '23 at 13:48
2

Working on Ubuntu 22.04. Thank you so much for this!! Nordlynx internet interface (NordVPN) came up in the UI dropdown which I was delighted about!!
I couldn't get 5Ghz working, not sure if it's my hardware problem or the software.
– Robert Rendell Jul 12 '23 at 17:37

score 6 · Answer 5 · edited Apr 13 '17 at 12:14

As you can see in the comments to this answer ther IS a way to do this. It's documented for FreeBSD (which is not Ubuntu/Linux) here: https://serverfault.com/questions/192144/connect-to-multiple-ap-with-one-wifi-adapter-under-linux-freebsd (Link from the comment). It does not seem to work exactly the same way on Linux, but it should be similar. Unfortunately I wasn't able to find more detailed information about this topic.

The probably easiest and most common way is using two physical network interfaces. So you may buy another wifi stick or just use another technology to connect further and do just one of them via Wifi. The possibilities are for example:

Bluetooth + Wifi
LAN/Ethernet + Wifi
3G/LTE + Wifi
Wifi (external) + Wifi (built-in or second external)

Once I noticed that Ubuntu Linux is capable of managing two wifi devices at once without being complicated. I did not test this in ways of sharing the internet connection etc, but it should be possible. The way how complicated it will be is probably depending of the type of connections you use. On Linux you probably do not need and kind of special software. It should be possible to share connections without the need for any special tools. Unfortunately I cannot try it at this time.

I recommend you try Wifi to Wifi if you have another wifi stick anyway and otherwise LAN or Bluetooth (which is built-in in most notebooks). 3G/LTE sharing is a bit bad because of providers dataplans and so on.

See this: Connect to multiple AP with one Wifi adapter under Linux/FreeBSD? — gertvdijk, Jul 25 '13 at 18:17
Wow, it even does not seem to be that hard to do. At least on FreeBSD. But I still think, if this is supposed to be used often and/or many devices are supposed to be routed through these two connections, it's better to use two physical network interfaces if available. Also it should be relatively easy configurable with the ubuntu network settings (gui). It's a very interesting idea, though. Surely useful in some cases. I noticed some things in my answer that are misunderstandable (and some as you noticed, wrong). I'll edit it. — verpfeilt, Jul 25 '13 at 19:52
setup multiple ap on one device is not same as setup ap and connect to another ap in same time. — QkiZ, Feb 12 '19 at 19:29

Mitch · Answer 6 · 2013-07-28T07:44:20.210

This was added as another answer because the other answer created so much controversy.

Most and foremost, you need to know the name of our wireless adapter. Use the below command to get it:

iwconfig

It would be most probably wlan0 or wlan1.

There are cases that we use old WiFi adapter and we want to know the driver it uses. We can use the below commands in accordance with it's type that is either USB or PCI.

lsusb
lspci

Use the below command to see which driver you currently use:

lsmod

Need to install a programs. Just press Ctrl+Alt+T on your keyboard to open Terminal. When it opens, run the command(s) below:

sudo apt-get install hostapd

Open the main network adapter configuration file by this command:

sudo gedit /etc/hostapd/hostapd.conf

And edit it like this:

interface=wlan0
driver=nl80211
country_code=US
ssid=mySSID
hw_mode=g
channel=1
wpa=2
wpa_passphrase=MyWiFiPassword
wpa_key_mgmt=WPA-PSK
wpa_pairwise=TKIP
rsn_pairwise=CCMP
auth_algs=1
macaddr_acl=0

The first line should be your network adapter name. The 2nd line should not be changed in most cases, unless you were not lucky and you require a 3rd party driver. The 3rd line does not require explanation. The 4th line should be your WiFi access point name (SSID). The fifth line identifies your network as a/b/g/n mode. The next line is your network channel. The remaining lines set security and encryption. In most cases, you only require to change pass phrase.

Open the 2nd configuration file by this command:

sudo gedit /etc/default/hostapd

And change it like this:

DAEMON_CONF="/etc/hostapd/hostapd.conf"
RUN_DAEMON="yes"
DAEMON_OPTS="-dd"

First line points to main network adapter configuration file. 2nd line tells hostapd to run in DAEMON mode in background on boot. The last line tells hostapd to log every message. The important trick here is if you like to use two different wireless network adapters to setup a Dual Band Access Point, you should create to separate original config files (1st file) for each ard and change it like this:

DAEMON_CONF="/etc/hostapd/hostapd.conf /etc/hostapd/hostapd2.conf"

The configurations are finished.

Running DAEMON

Now you have to ensure that hostapd DAEMON starts on boot (1st command below), you should also run it now to avoid a mandatory reboot.

sudo update-rc.d hostapd defaults
sudo /etc/init.d/hostapd start

And it is finished. Now we can connect to our newly built access point.

^{Sources:Hostapd:The Linux Way to create Virtual Wifi Access Point & Hostapd Linux documentation page}

You said with your own words: "You need to know the name of the network adapter that you connect to the internet on. This must be different from the network adapter you configured above", but you specified the same: "ie wlan0". Also in the given source is specified very clear in the Concept section: "You need to have 2 interfaces, one which accesses the net (e.g. eth0), and other which provides the access point services (e.g. wlan0)". — Radu Rădeanu, Jul 28 '13 at 05:07
I think that the OP wants to use the same adapter: "But when I am browsing internet WiFi internet connection and I want to create a wireless hotspot the WiFi internet is disconnected". And gertvdijk specified this when he start the bounty. — Radu Rădeanu, Jul 28 '13 at 07:25
In my opinion the previous version was better (but is just an opinion). — Radu Rădeanu, Jul 28 '13 at 15:13

score 3 · Answer 7 · answered Oct 07 '22 at 05:43

3

Install linux-hotspot.

sudo add-apt-repository ppa:lakinduakash/lwh
sudo apt install linux-wifi-hotspot

answered Oct 07 '22 at 05:43

Moyo Freeman

335

Already answered by Lakindu Akash – Zatigem Jul 22 '23 at 14:22

score 1 · Answer 8 · answered Jul 27 '13 at 11:18

1

Its currently possible only for Atheros Cards and a very few Broadcom cards. To know which one you are using, please run the following command in terminal and paste the output here:-

lspci | Wireless

Or you can just straightforward try out that method. Here is the link for tutorial on how to do that:- connectify-for-linux-with-single-wireless-interface

answered Jul 27 '13 at 11:18

vasishath

129

Please include the essential steps in the answer. Currently this is just a link-only answer which is frowned upon. It looks like a good source and instructions, so +1, but please improve your answer. – gertvdijk Jul 27 '13 at 19:22

score 1 · Answer 9 · edited Feb 23 '14 at 08:20

The best way I have found to create a CONNECTIFY EXPERIENCE is to use AP-HOTSPOT!
(WPA2..not wep like linux does by default in ubuntu)

sudo add-apt-repository ppa:nilarimogard/webupd8

sudo apt-get update

sudo apt-get install ap-hotspot

To Run and Options

Start: sudo ap-hotspot start

Stop: sudo ap-hotspot stop

Configure: sudo ap-hotspot Configure

Want a Graphical User Interface?

To install it open up a terminal, then browse to with:

cd /home/USERNAME/LOCATION

Then run the install commands:

qmake

make

Creates a program... Drag it to desktop and done :) cheers

As far as two adapters... Windows and free bsd can do it... As of now i'm still trying to figure it out as I only approached this scenario for myself as of yesterday! I will report back... Linux can do it as well.. It is not an hardware limitation for the adapters that can do it with other operating systems...

Welcome to AskUbuntu. Henceforth please avoid using all capitals in your messages. It can be perceived as offending or aggressive. — Luís de Sousa, Feb 23 '14 at 07:59
This is the most straightforward WORKING solution to set up hotspot from a device connected with a cable to internet. — jmary, Jun 17 '17 at 10:22

score 0 · Answer 10 · answered May 03 '20 at 07:41

0

on latest ubuntu (04.20) - there is a built in options in the wifi settings. so when you turn on wifi, you have the 3-dots button on top - one of the options there is "turn on hotspot", there, you'll set the wifi SSID and password, and that's it. Note: every wifi adapter can be used only for one action at once - or hotspot of connect to network. so if you have only one adapter and you're connected only via wifi - won't do...

answered May 03 '20 at 07:41

drizzt13

111

1

So this is NOT and answer to the question if it only allows one connection. The question is explicitly about a wifi-to-wifi hotspot using one adapter. – Kvothe Aug 22 '20 at 19:55

score 0 · Answer 11 · answered Dec 16 '17 at 02:26

Like Purushoth's answer, this answer also requires 2 WiFi adapters (ex: one internal and 1 external USB Wi-Fi adapter). I couldn't get his answer to work for me, however, so here's what I did instead.

Tested in Xubuntu 14.04.

How to configure the Ubuntu/Xubuntu PC as a WiFi hotspot (ex: for use in airports or on airplanes in order to share a single, paid connection from your PC with your phone and other devices):

Plug in a USB WiFi dongle. Not all dongles can act as an “ap” (Access Point), but the internal card can for sure, so we will (for now at least, until you can find a USB wifi adapter that can act as an access point) use the external USB one to connect to the paid service (ex: in-flight WiFi), and we will use the internal wifi adapter to make the wifi access point.
- IMPORTANT: DO NOT PAY FOR AND CONNECT TO THE PAID SERVICE WITH THE WRONG (external) WIFI ADAPTER, OR ELSE YOU'LL HAVE TO PAY AGAIN TO SWITCH IT, AS YOUR PAID CONNECTION IS SOMEHOW LINKED TO YOUR WIFI ADAPTER—PROBABLY VIA ITS PERMANENT MAC ADDRESS OR SOMETHING.
Left click the wifi icon in the panel and choose “Create New WiFi Network...” → choose the internal Wi-Fi adapter (which is wlan0), make up a Network name (SSID) (ex: “wifi-hotspot”), choose “WPA & WPA2 Personal” for “Wi-Fi security”, and make up a password, then click “Create”.
- NB: THERE'S A BUG THAT MAKES YOU SOMETIMES UNABLE TO SELECT THE INTERNAL WIFI ADAPTER FOR THIS STEP WHEN YOU ALSO HAVE AN EXTERNAL USB WIFI ADAPTER PLUGGED IN. IF THIS HAPPENS, SIMPLY UNPLUG THE EXTERNAL WIFI ADAPTER WHILE DOING THIS STEP TO MAKE THE WIFI HOTSPOT, then plug it back in when done/when told to below.
Edit the configuration file for the new wifi hotspot you just created:
- cd /etc/NetworkManager/system-connections
- ls
- Find your hotspot file you just created via the GUI step above; ex: “wifi-hotspot”, and edit it:
- sudo nano wifi-hotspot
- Arrow down and change “mode=adhoc” or whatever it says to “mode=ap”. Save and exit.
Now, with the external USB WiFi adapter still UNplugged, activate the wifi hotspot you just created by left-clicking the WiFi icon in the panel again and going to “Connect to Hidden WiFi Network...” → choose your internal wifi adapter again for “Wi-Fi adapter”, and choose the access point name (ex: “wifi-hotspot”) for “Connection.” The “Network name,” “Wi-Fi security,” and “Password” fields will now auto-fill and grey out. Click “Connect”. The WiFi Access Point will be activated on your internal card. You can connect your devices, such as your phone, to it.
Finally, with your WiFi hotspot active, plug your secondary/USB WiFi adapter in and use it to connect to the paid network. Pay for your subscription or whatever and your internet through this adapter will now automatically be broadcast out to devices connected in to you through your internal “Access Point” adapter you just configured.
Done!

References: Here is where I found the /etc/NetworkManager/system-connections folder path & an alternate approach (that didn't work for me): https://askubuntu.com/a/609199/327339

I didn't overlook that part of the question. However, if the most-upvoted answer (by @Purushoth) gets to be the most upvoted, and also does NOT use a single adapter (it requires plugging in an external Ethernet connection to feed in internet to the PC), then I figured it would be ok for me to answer the question requiring internet IN through ethernet and internet OUT through a single wireless adapter access point as well. This is especially considering the most-upvoted answer, which requires ethernet and wifi, didn't work for me. — Gabriel Staples, Feb 12 '19 at 20:22
I used https://github.com/oblique/create_ap and it works on single adapter. Check if it works for you. — QkiZ, Feb 13 '19 at 12:26