On the Beagleboard you should expect to require a swap file given the limitation of how little RAM is available (between 256 MB and 512 MB). Some system programs like apt-get will only run properly when some swap space is present (due to 256 MB not being enough RAM). Some images (such as those from Linaro.org) do not come with a swap partition or any swap space allocated. Under Linux, swap space can be either a dedicated partition or a swap file. Both can be mounted as swap which the OS can access. Creating a Swapfile The following commands will create a 512MB file, limit access only to root, format it as swap and then make it available to the OS: sudo mkdir -p /var/cache/swap/ sudo dd if=/dev/zero of=/var/cache/swap/swapfile bs=1M count=512 sudo chmod 0600 /var/cache/swap/swapfile sudo mkswap /var/cache/swap/swapfile sudo swapon /var/cache/swap/swapfile To tell the OS to load this swapfile on each start up, edit the /etc/fstab file to include the following addi
Tcpdump is a common packet analyzer that runs under the command line. It allows the user to display TCP/IP and other packets being transmitted or received over a network to which the computer is attached.[3] Distributed under the BSD license,[4] tcpdump is free software. Tcpdump works on most Unix-like operating systems: Linux, Solaris, FreeBSD, DragonFly BSD, NetBSD, OpenBSD, OpenWrt, macOS, HP-UX 11i, and AIX. In those systems, tcpdump uses the libpcap library to capture packets. The port of tcpdump for Windows is called WinDump; it uses WinPcap, the Windows port of libpcap. I've read through a lot of how-to articles in the past. and this article "TCPDUMP Tutorial with Examples" is the most thorough, most intuitive articles that I've read.