raspberry_router

how to set up a Raspberry Pi as an access point(Router)

if you can't understand what I had saying, you can use the google translation translate the README.CN.md

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this program is a preview of change a raspberry as a router and a ntp server.

from https://www.raspberrypi.org/documentation/configuration/wireless/access-point.md and https://vitux.com/how-to-install-ntp-server-and-client-on-ubuntu/

And I could install nextcloud and wordpress to change the raspberry as a smart route

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It depanded raspbian-2019-07

1. First we should install these bags

sudo apt update
sudo apt -y upgrade
sudo apt -y install dnsmasq hostapd
sudo systemctl stop dnsmasq
sudo systemctl stop hostapd

We will use the nano as editer,if you like to use vi/vim or other, change it and use it.

2. Configuring a static IP

We are configuring a standalone network to act as a server, so the Raspberry Pi needs to have a static IP address assigned to the wireless port.

sudo nano /etc/dhcpcd.conf

Go to the end of the file and edit it so that it looks like the following:

interface wlan0
    static ip_address=192.168.4.1/24
    nohook wpa_supplicant

We shoud know that the "ip_address" shoud be set as different as the address on the eth0. And you can change the number of the ip_address, but it should be access the rule of the address.

Someone maybe tell you that you should change the file /etc/network/interfaces but this file has been abandoned. So you shoud change the file /etc/dhcpcd.conf

Now restart the dhcpcd daemon and set up the new wlan0 configuration:

sudo service dhcpcd restart

3. Configuring the DHCP server

Rename this configuration file, and edit a new one:

sudo mv /etc/dnsmasq.conf /etc/dnsmasq.conf.orig
sudo nano /etc/dnsmasq.conf

And add these on the end

interface=wlan0      
dhcp-range=192.168.4.2,192.168.4.249,255.255.255.0,24h

When we set the wlan0 ip address, we use the "192.168.4.1/24",so we set the dhcp-range is the "192.168.4.2,192.168.4.249" and the "/24" main as "255.255.255.0" .

Reload dnsmasq to use the updated configuration:

sudo systemctl reload dnsmasq

4. Configuring the access point host software

You need to edit the hostapd configuration file, located at /etc/hostapd/hostapd.conf, to add the various parameters for your wireless network. After initial install, this will be a new/empty file.

sudo nano /etc/hostapd/hostapd.conf

and change it as down

interface=wlan0
# use the wlan0 as ap
driver=nl80211
# use the drive nl802.11
ssid=NameOfNetwork
# your wireless ssid
hw_mode=g
# the mode you could use
channel=7
wmm_enabled=0
macaddr_acl=0
auth_algs=1
ignore_broadcast_ssid=0
wpa=2
wpa_passphrase=AardvarkBadgerHedgehog
# your ssid password
wpa_key_mgmt=WPA-PSK
wpa_pairwise=TKIP
rsn_pairwise=CCMP

defferent hw_mode can use different HZ

• a = IEEE 802.11a (5 GHz)
• b = IEEE 802.11b (2.4 GHz)
• g = IEEE 802.11g (2.4 GHz)
• ad = IEEE 802.11ad (60 GHz)

We now need to tell the system where to find this configuration file.

sudo nano /etc/default/hostapd

Find the line with #DAEMON_CONF, and replace it with this:

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

5. Start it up We should start the service of hostapd and dnsmasq

sudo systemctl unmask hostapd
sudo systemctl enable hostapd
sudo systemctl start hostapd
sudo systemctl restart dnsmasq

And we should check the status of these service

sudo systemctl status hostapd
sudo systemctl status dnsmasq

6. Add routing and masquerade

Before we start, you maybe should reboot your raspberry pi

sudo reboot

Edit /etc/sysctl.conf and uncomment this line:

net.ipv4.ip_forward=1

Add a masquerade for outbound traffic on eth0:

sudo iptables -t nat -A  POSTROUTING -o eth0 -j MASQUERADE

Save the iptables rule.

sudo sh -c "iptables-save > /etc/iptables.ipv4.nat"

Edit /etc/rc.local

sudo nano /etc/rc.local

and add this just above "exit 0" to install these rules on boot.

iptables-restore < /etc/iptables.ipv4.nat

Reboot and ensure it still functions.

Then we install the ntp server

7. update and upgrade

sudo apt update && sudo apt -y up grade

8. install ntp server

sudo apt install ntp

9. Switch to an NTP server pool closest to your location

sudo nano /etc/ntp.conf

and you can find NTPPools on this site

https://support.ntp.org/bin/view/Servers/NTPPoolServers

You can choose a NTPPool near your location.

10. Restart the NTP server and Verify that the NTP Server is running

sudo service ntp restart
sudo service ntp status

if you can't understand what I had saying, you can use the google translation translate the README.CN.md