Raspberry Pi

Network

Detect all Raspberry Pi on local network

From [1].

sudo nmap -sP 192.168.1.0/24 | awk '/^Nmap/{ip=$NF}/B8:27:EB/{print ip}'

where 192.168.1.* will be your local network mask.

We can also simply look for string Raspberry since nmap correctly identifies pi mac address:

sudo nmap -sP 192.168.1.0/24 | grep -B2 Raspberry

where 192.168.1.* will be your local network mask.

Raspberry in BRIDGE mode

Methods above fail if Raspberry is setup to bridge wlan0-eth0 connections. In that case, the visible MAC address is the one of the wlan0 interface. It can be detected because the address will be reported twice:

sudo nmap -sP 172.19.2.0/23|sort|uniq -d
# Host is up (0.18s latency).
# MAC Address: 00:0F:13:05:46:C2 (Nisca)              <-- MAC address of the Pi in bridge mode
# MAC Address: 80:86:F2:99:56:B5 (Intel Corporate)

Now we can repeat the request above to get the IP address:

sudo nmap -sP 172.19.2.0/23 | awk '/^Nmap/{ip=$NF}/00:0F:13/{print ip}'

Setup Pi as WiFi HotSpot (router)

This setup the Pi has a WiFi access point (AP) in router mode (NAT).

References:

• https://learn.adafruit.com/downloads/pdf/setting-up-a-raspberry-pi-as-a-wifi-access-point.pdf — THIS METHOD WORKS
• https://learn.adafruit.com/setting-up-a-raspberry-pi-as-a-wifi-access-point/overview
• http://blog.sip2serve.com/post/48420162196/howto-setup-rtl8188cus-on-rpi-as-an-access-point
• http://blog.sip2serve.com/post/48899893167/rtl8188-access-point-install-script

Setup Pi as WiFi HotSpot (bridge)

References:

• http://www.daveconroy.com/turn-your-raspberry-pi-into-a-wifi-hotspot-with-edimax-nano-usb-ew-7811un-rtl8188cus-chipset/

diff --git a/default/hostapd b/default/hostapd
index 1e12174..5783c15 100644
--- a/default/hostapd
+++ b/default/hostapd
@@ -7,7 +7,7 @@
 # file and hostapd will be started during system boot. An example configuration
 # file can be found at /usr/share/doc/hostapd/examples/hostapd.conf.gz
 #
-#DAEMON_CONF=""
+DAEMON_CONF="/etc/hostapd/hostapd.conf"
 
 # Additional daemon options to be appended to hostapd command:-
 # 	-d   show more debug messages (-dd for even more)
diff --git a/default/isc-dhcp-server b/default/isc-dhcp-server
index df30daa..ec7fb5a 100644
--- a/default/isc-dhcp-server
+++ b/default/isc-dhcp-server
@@ -18,4 +18,4 @@
 
 # On what interfaces should the DHCP server (dhcpd) serve DHCP requests?
 #	Separate multiple interfaces with spaces, e.g. "eth0 eth1".
-INTERFACES=""
+INTERFACES="wlan0"
diff --git a/dhcp/dhcpd.conf b/dhcp/dhcpd.conf
index e4368e7..cff23f9 100644
--- a/dhcp/dhcpd.conf
+++ b/dhcp/dhcpd.conf
@@ -10,15 +10,15 @@
 ddns-update-style none;
 
 # option definitions common to all supported networks...
-option domain-name "example.org";
-option domain-name-servers ns1.example.org, ns2.example.org;
+#option domain-name "example.org";
+#option domain-name-servers ns1.example.org, ns2.example.org;
 
 default-lease-time 600;
 max-lease-time 7200;
 
 # If this DHCP server is the official DHCP server for the local
 # network, the authoritative directive should be uncommented.
-#authoritative;
+authoritative;
 
 # Use this to send dhcp log messages to a different log file (you also
 # have to hack syslog.conf to complete the redirection).
@@ -105,3 +105,17 @@ log-facility local7;
 #    range 10.0.29.10 10.0.29.230;
 #  }
 #}
+
+subnet 192.168.42.0 netmask 255.255.255.0 {
+  range 192.168.42.10 192.168.42.50;
+  option broadcast-address 192.168.42.255;
+  option routers 192.168.42.1;
+  default-lease-time 600;
+  max-lease-time 7200;
+  option domain-name "local";
+  # option domain-name-servers 8.8.8.8, 8.8.4.4;
+  option domain-name-servers 164.129.147.251, 10.129.252.253;
+}
+
+
+
diff --git a/hostapd/hostapd.conf b/hostapd/hostapd.conf
new file mode 100644
index 0000000..1ee2984
--- /dev/null
+++ b/hostapd/hostapd.conf
@@ -0,0 +1,13 @@
+interface=wlan0
+driver=rtl871xdrv
+ssid=TESTMOBILE
+hw_mode=g
+channel=8
+macaddr_acl=0
+auth_algs=1
+ignore_broadcast_ssid=1
+wpa=2
+wpa_passphrase=Framb0ise
+wpa_key_mgmt=WPA-PSK
+wpa_pairwise=TKIP
+rsn_pairwise=CCMP
diff --git a/iptables.ipv4.nat b/iptables.ipv4.nat
new file mode 100644
index 0000000..3991461
--- /dev/null
+++ b/iptables.ipv4.nat
@@ -0,0 +1,18 @@
+# Generated by iptables-save v1.4.14 on Mon Apr 27 09:39:52 2015
+*nat
+:PREROUTING ACCEPT [7:840]
+:INPUT ACCEPT [7:840]
+:OUTPUT ACCEPT [2:133]
+:POSTROUTING ACCEPT [0:0]
+-A POSTROUTING -o eth0 -j MASQUERADE
+COMMIT
+# Completed on Mon Apr 27 09:39:52 2015
+# Generated by iptables-save v1.4.14 on Mon Apr 27 09:39:52 2015
+*filter
+:INPUT ACCEPT [99:8128]
+:FORWARD ACCEPT [0:0]
+:OUTPUT ACCEPT [54:6210]
+-A FORWARD -i eth0 -o wlan0 -m state --state RELATED,ESTABLISHED -j ACCEPT
+-A FORWARD -i wlan0 -o eth0 -j ACCEPT
+COMMIT
+# Completed on Mon Apr 27 09:39:52 2015
diff --git a/network/interfaces b/network/interfaces
index 99135c9..a3c1b53 100644
--- a/network/interfaces
+++ b/network/interfaces
@@ -3,13 +3,29 @@ auto lo
 iface lo inet loopback
 iface eth0 inet dhcp
 
-auto wlan0
-allow-hotplug wlan0
-iface wlan0 inet manual
-wpa-roam /etc/wpa_supplicant/wpa_supplicant.conf
-
-iface home inet static
-    address 172.19.100.107
-    netmask 255.255.0.0
-    gateway 172.19.3.1
+# auto config for home network
+# ----------------------------
+# auto wlan0
+# allow-hotplug wlan0
+# iface wlan0 inet manual
+# wpa-roam /etc/wpa_supplicant/wpa_supplicant.conf
+#
+#iface home inet static
+#    address 172.19.100.107
+#    netmask 255.255.0.0
+#    gateway 172.19.3.1
+
+# Config for wifi hotspot
+# -----------------------
+#allow-hotplug wlan0
+#iface wlan0 inet static
+#  address 192.168.42.1
+#  netmask 255.255.255.0
+#
+#up iptables-restore < /etc/iptables.ipv4.nat
+
+# Config for bridged mode
+auto br0
+iface br0 inet dhcp
+bridge_ports eth0 wlan0
 
diff --git a/sysctl.conf b/sysctl.conf
index 52e7256..3f57b5c 100644
--- a/sysctl.conf
+++ b/sysctl.conf
@@ -25,7 +25,7 @@ kernel.printk = 3 4 1 3
 #net.ipv4.tcp_syncookies=1
 
 # Uncomment the next line to enable packet forwarding for IPv4
-#net.ipv4.ip_forward=1
+net.ipv4.ip_forward=1
 
 # Uncomment the next line to enable packet forwarding for IPv6
 #  Enabling this option disables Stateless Address Autoconfiguration

The following changes might be required as well:

diff --git a/default/hostapd b/default/hostapd
index 5783c15..1d640ee 100644
--- a/default/hostapd
+++ b/default/hostapd
@@ -17,4 +17,4 @@ DAEMON_CONF="/etc/hostapd/hostapd.conf"
 # Note that -B (daemon mode) and -P (pidfile) options are automatically
 # configured by the init.d script and must not be added to DAEMON_OPTS.
 #
-#DAEMON_OPTS=""
+DAEMON_OPTS="-d -dd"
diff --git a/rc.local b/rc.local
index 7d39ed7..166b2cd 100755
--- a/rc.local
+++ b/rc.local
@@ -17,4 +17,6 @@ if [ "$_IP" ]; then
   printf "My IP address is %s\n" "$_IP"
 fi
 
+/usr/sbin/ifplugd -i wlan0 --kill
+
 exit 0

Troubleshoot

403 Forbidden when apt-get upgrade

From [2]:

Err http://mirrordirector.raspbian.org/raspbian/ wheezy/main libc-dev-bin armhf 2.13-38+rpi2+deb7u8           
  403  Forbidden
Err http://mirrordirector.raspbian.org/raspbian/ wheezy/main libc6-dev armhf 2.13-38+rpi2+deb7u8              
  403  Forbidden

Edit /etc/apt/apt.conf:

-deb http://mirrordirector.raspbian.org/raspbian/ wheezy main contrib non-free rpi
+#deb http://mirrordirector.raspbian.org/raspbian/ wheezy main contrib non-free rpi
+deb http://archive.raspbian.org/raspbian wheezy main contrib non-free
+deb-src http://archive.raspbian.org/raspbian wheezy main contrib non-free