I'm looking for an image which will boot quickly (I assume it'll be linux) and have LAN drivers- for sending TCP / UDP packets to another system in the same network. Ideally, if possible, I would like to have an image with a parameter - the destination address for sending the packets but otherwise I'll just send - broadcast. what tools / types/ OS would suit this situation?
Any live Linux distribution will work just fine for this.
The best answer to this question will depend on (1) how fast is "fast", (2) how exotic the hardware you need to support is and (3) how robust of a system you want after boot.
There are a good number of Linux distribution aimed at being small and a good number that provide live images. The intersection of these two sets is also fairly large. If the lan drivers you need are for a basic wired ethernet card, then many "generic" distributions will likely work for you.
Beyond those that Gilles mentioned, here are a few options you may want to look into:
grml: This is a Debian-based live-CD intended for system administrators. You might want to get the "small" image since you are worried about boot speed. The system you are left with is an incredibly functionally system with a wide range of command-line tools.
Debian Live: Debian Live provides a set of tools that allows you to customize your own live image of a Debian system. You can create a pretty lean system through customization.
You will have to download the needed linux source from the kernel.org.
Install the development tools. For eg. in Fedora
yum groupinstall "Development Tools"
yum install ncurses-devel
yum install qt-devel
Then untar the source code and place it in /usr/src/kernels/
Then go inside the source and do a
After that add the necessary modules needed for your kernel. If you are concentrating on Network, do it inside the Network options.
After adding the necessary options save the profile and exit. Then do the following
make && make modules && make modules_install && make install
Now check your grub.conf under /boot/grub/grub.conf and make sure you have the configuration for your kernel in it.
Now you can add the program which does to the initrd image.
The initrd has an init function... modify the init function, to include your custom function.
A linux kernel image with a custom initramfs that suits your needs (i.e. includes said program to send said packets).