I have never had the privilege of working in an environment that required complicated routing or if it did require it, it was handled upstream of me. I've always used very simple static routing configurations and never needed to do any multipath routing -- hence my general confusion regarding this subject. I would like to understand multicasting and anycasting better. 


What is the difference between unicast, anycast, broadcast and multicast traffic?
What situations are they generally used in and why (e.g., what applications use which method)?
How do you calculate how much broadcast traffic is too much for a given network segment or broadcast domain?
What are the security implications of allowing broadcast and multicast traffic?



Question: How do I repair a floor joist which has a hole drilled less than 2 inches from the bottom?
Answer: Whilst not a direct answer this thread will give you all the detail you require:
http://www.homeownershub.com/uk-diy/filling-holes-in-joists-280701-.htm

I'd advise leaving them alone if no sagging has occurred.