How to configure a computer as a hotspot?

Question

I use OpenSuse 13.1 (with KDE). On my phone I can turn on a hotspot just by pushing a button. I have been researching how to do this on linux, I haven't found an easy way yet.

What I want to achieve: I have a wired connection. I want to share this through a wireless connection (so that my phone can access the internet).

I read that I could do this with an ad-hoc network. Is this correct or is this something different still? I did try this, new network (regular and shared I tried) -> mode: ad-hoc -> I gave in a ssid "hotspot".

But it is not being detected by my phones. Perhaps ad-hoc is not allowed for them?

Any suggestions?

-- update

I have added the steps I have tried graphically:

1. Add new network: I need to choose between wireless and shared. I have tried both. But I presume it is wireless?

2. Set a name and as ad-hoc (or infrastructure) network. -> none of the two seems to be detected by android or iphone.

3. I am connected by cable, do I also need to connect to the wireless (by dubble clicking it?)

Am I missing something obvious? Or a missing host service/server? Etc... because none of the ad-hoc or infrastructure networks are showing on my cell phone.

I am using knetworkmanager now (kde). If I can do it command line, would also be ok.

--update

I have executed the following commands error free:

   nmcli nm wifi off
    rfkill unblock wlan

    ip link set dev wlp1s0 up
    ip address add 192.168.5.1/24 dev wlp1s0

    iptables -t nat -A POSTROUTING -s 192.168.5.0/24 -o enp0s20u2 -j MASQUERADE
    sysctl -w net.ipv4.ip_forward=1 1> /dev/null

    systemctl start hostapd.service
    systemctl start dnsmasq.service

My /etc/hostapd is:

interface=wlp1s0
driver=nl80211
# bridge=br0
channel=3
hw_mode=g
auth_algs=1
ssid=test

My phone sees the test network. But keeps saying "Obtaining IP address...."

I feel that I am very close now...

Answer 1

I don't know about Windows Phones or iPhones, but Android phones cannot detect ad-hoc networks out of the box. You will probably need to use infrastructure mode in order for your phone to see your network. Alternatively, search for Android add-ons that enable connections to ad hoc wifi networks (success seems dependent on the device and Android version).

Answer 2

1. Install HostAPD:

    yast -i hostapd

1. Configure hostapd in the file /etc/hostapd.conf, especially consider the settings (ESSID will be test, driver will be for the WLAN driver, bridge will be for the bridge you create later on, channel is arbitrary, hw_mode=g means the speed as in A/B/G/N).

    driver=nl80211
    bridge=br0
    channel=3
    hw_mode=g
    auth_algs=1

1. Start hostapd:

    hostapd /etc/hostapd.conf

1. verify that you see a WLAN with the ESSID test, e.g. on a mobile phone

2. add a network bridge on your Linux computer (assuming wlan0 is your wireless network device and 192.168.0.5 is a free IP address in your subnet):

    brctl addif br0 wlan0
    ifconfig br0 192.168.0.5

1. now you will probably want to have your Linux computer as a NAT gateway into the internet so you will do about (assuming ppp0 is the device you use to get into the internet as it is typically the case with UMTS modems):

    echo 1 > /proc/sys/net/ipv4/ip_forward
    iptables -t nat -A POSTROUTING -o ppp0 -j MASQUERADE
    iptables -A FORWARD -i br0 -j ACCEPT
    iptables -A FORWARD -i wlan0 -j ACCEPT 

1. Now you will want to have your Linux computer as dhcp server so connecting devices will be informed that this computer is their gateway.

2. Now you will want to introduce security features like WPA so your communication cannot be evesdropped.

I blogged this under http://www.linuxintro.org/wiki/Set_up_a_wireless_accesspoint

Answer 3

Have you tried the ap-hotspot method? It takes your Ethernet cable and sends it out wirelessly. Not as ad-hoc. That is something else, I use the method quite often.

Article here.

Anyway, here's how it works. You can think of this as reverse tethering as long as you are Ethernet-connected. I wrote the article quite a long time ago, so I know it works but other than what's written there, don't know what else I can say.