Stove exhaust vent moving and closing an old one

I am remodeling my kitchen … selecting cabinets. Right now we have a dishwasher next to the stove. The cabinet designer suggested that keeping them next to each other is a big “no”. They suggested a cabinet (15” or 24”) between stove and dishwasher. Not a bad idea BUT this would require moving the exhaust vent. I am wondering how to close the old one (venting to outside). My contractor says to make a new one is not a difficult work BUT who knows in this old house what we will encounter. Also how do you close the old one? Do we need to purchase siding and reside the whole side of the house? I asked if there were caps to close the old went … but he wants to go with the siding idea ($$$) … I am trying to keep the budget. Any thoughts … advice please? Is it really horrible to keep stove next to dishwasher? It never bothered me until it was pointed out … who makes these rules?  คาสิโนออนไลน์ขั้นต่ำ10บาท