13 months and an iron will

I have a stunning 13 month old son and a 3yr old daughter.My son is a huge mischief which is fine and normal. He however finds being told no (no matter how firmly) hilarious. Typical boy fashion any reaction is a good reaction and he is going to find it funny. He also is incredibly focused. I could take him to the other end of the property and the moment I let go of him he would be back to ripping out the internet cables. You cannot distract him and he is incredibly stubborn.He is really strong and tall for his age, as tall almost as daughter was at 2. It's been an upward battle since he was nine months old when he started walking. Any advice on how to install boundaries and age appropriate discipline would be hugely welcome. We currently use time outs and just talking to our daughter. She is hugely responsive to that and hasn't really thrown us many curve balls. Also we live in a country were smacking is illegal. But our parents generation who voted that in seem to only recommend smacking as a solution.Thank you so much!!! via /r/Parenting https://ift.tt/2LIAGxC