Creating Your BeagleBone Black Development Environment - BeagleBone for Secret Agents - page 12

Streamlining the SSH connections
Even if you don't use Emacs, you'll find yourself frequently connecting to the BBB with
SSH. If you run the BBB from the USB cable attached to your PC, then the default Internet
Protocol (IP) address of the BBB will be 192.168.7.2 . However, if you want to down-
load software directly to the BBB, as you will need to do in order to complete these pro-
jects, you'll have to forward your Internet connection from the PC to the BBB. Also, when
powered from the USB directly, there is typically a 500mA current limit. When the BBB is
powering expansion boards or other peripherals, it'll need to be powered from a 5V DC
plug that can supply up to 1A. As a result of these two issues, you may find it much more
convenient to run the BBB from a 5V power supply and connect the Ethernet cable into
your home network directly.
When you do this, the IP address will most likely be assigned by your router and will only
be known to your router. This will leaving you staring at the BBB pontificating over its IP
address.
Discovering the IP address of your networked BBB
There are a few ways to discover the IP address of your device. The first way is to log in to
your router and look up the IP address. This is a quick method but as there are numerous
routers, you'll have to consult your router's documentation on how to accomplish this.
You can also use the nmap utility to conduct a quick ping scan on your network. Assum-
ing that you are familiar with the IP address of your own network, you should be able to
see a new device. If you are running an apt-based distribution, you can install nmap with
sudo apt-get install nmap . If you are on a Mac, you can use the homebrew
package manager ( http://brew.sh/ ) and install it with brew install nmap . Windows
users should download the binary from http://nmap.org/download.html#windows . Once it
is installed, you'll want to run a command similar to the following:
nmap -sn 192.168.1.0/24
Replace 192.168.1.0 with the appropriate address for your network. /24 is the Class-
less Inter-Domain Routing ( CIDR ) notation for the subnet mask. In this case, /24 means
use a subnet mask of 24 bits of 1's, or 255.255.255.0 . The -sn option directs nmap to
conduct a ping scan.