Badly, unless the connection you need is a fibre one. There is no railway station in the town. Just over half the working population drives. A third of them never leave the house to do it. Ferndown is superbly connected to the internet and loosely attached to everything else.
Rail is the missing piece and it is missing completely. The nearest station is at Branksome, outside the town, and the share of residents commuting by train is 0.1%, which is less a travel choice than a statistical curiosity. Buses do exist, and there are 68 stops across the area, but the share of residents commuting by bus is about 1%. The infrastructure is present. The habit is not.
What the town actually does is drive, or stay in. Around 55% of residents commute by car, and roughly 33% work from home, which between them account for the overwhelming bulk of the working population. Walking takes about 5% and cycling around 2%. Roughly 47% of households run two or more cars, and only about 13% have none at all. A second car here is not a luxury purchase, it is the price of the second adult having a job.
For everyday trips, the Department for Transport's modelled journey times put the nearest town centre at about 9 minutes by car and around 15 minutes by public transport. That gap is small by rural standards, which is the strongest thing the bus network has going for it.
Broadband is the compensation and it is a real one. Gigabit-capable connections reach about 69% of premises, superfast reaches around 96%, and only about 0.4% of premises fall below the universal service obligation. For a town with no station, being able to work from the spare bedroom at speed is not a consolation prize, it is the entire reason a third of the place can live here at all.
Mobile coverage is a non-issue. Every premises has four or five gee service from at least one operator, and around 97% have it from all of them.
On electric vehicles, the area has 4 public charge points, 2 of them rapid.
The full modelled picture for the town centre runs to about 9 minutes by car, 15 by public transport, 12 by bicycle and 19 on foot. Those are national statistics modelled for the area rather than a route timed from any particular driveway, so treat them as the shape of the place rather than your own commute.
The same source puts a doctor's surgery at roughly 8 minutes by car, 16 by public transport and 17 on foot, and a food store at about 7 minutes by car or 8 on foot, which is the genuinely convenient end of the town's geography. A hospital is around 26 minutes by car and about 48 by public transport, and the modelled walk is roughly 119 minutes, which is the polite way of saying nobody walks to hospital from here. Employment centres come out at about 9 minutes by public transport against roughly 18 by car, one of the few figures in this whole answer that favours the bus. One important caveat applies to all of them: the public transport figures date from 2019 and services have been withdrawn across the country since, so the car and walk times have aged far better than the bus ones.
Current bus data tells a more encouraging story than the commuting share does. Across the 49 stops with service information, the average is around 31 scheduled departures on a weekday, with about 2 buses an hour at peak, and roughly 92% of stops keep some weekend service. That is a functioning network by the standards of a small Dorset town. It is also two an hour at the busiest point of the day, and two an hour is a service you plan your life around rather than one you turn up for.
Road noise is the one environmental cost of sitting next to a trunk route. Close to 100% of the town's postcodes fall near or above 65 decibels, the level at which official noise mapping treats road noise as significant, and the loudest band present in the area reaches 75 decibels. Rail noise does not register at all, which is unsurprising given the absence of a railway. Where any individual house sits within that range depends entirely on which side of the town it is on.
Charging an electric car locally means the 4 public charge points, offering 7 connectors between them, of which 2 are rapid. With rapid units in single figures, public charging here is something you schedule rather than something you do while picking up a loaf. Anyone going electric in Ferndown is realistically charging on a driveway, which, given the housing stock, most people have.
Connectivity is the weakest part of the case for this town, and the broadband is doing an enormous amount of work to disguise it. Fine if your commute is a staircase, awkward if it involves a platform.