The most delightful 9 year old dog. He is a Scottish Terrier x Jack Russell. As soon as someone arrives at the gate he starts to bark and jumps up at them. As soon as I engage in any form of conversation he jumps up/barks or licks the guest. What would be the best solution to overcome this problem.

Obedience.

Socialization

Correction and redirecting his attention elsewhere.

Award good behaviors. Ignore or even punish bad behaviors

If he is completely out of control, put him away. Bad dogs don't get to participate with the pack. And until you have some rules set in stone, removing him from the situation will be easiest. If he cannot be bad, he won't display bad behaviors. It also won't re-enforce his bad behaviors.

Start with obedience passes. You'll he surprised what 6-8wks will do for the both of you. If he is obedience trained, go to classes for the socialization.