And you can install either LinBPQ or JNOS to do packet without the complexity of dealing with the Linux AX.25 stack. (Not saying that LinBPQ or JNOS are less complex....)
The Linux AX.25 stack comes with the kernel and is installed on our image and configured with my scripts taking the complexity out of dealing with Linux AX.25 stack. Bill you should try it some time.
You can use LinBPQ or JNOS, I think they are good pieces of software but I don't support them.