You can do either.

I tend to add each train separately, as it makes things easier if there are delays etc that mean I have to take a later train. (Or, sometimes, an earlier one!)

It is best to search timetables on Bahn.com, rather than in the app, It’s more reliable.

You’ll need a reservation on the IC from Genoa to Milan, €3. And on the EC from Milan to Switzerland, €11.

Best information on reservations, and where to buy them, here: https://www.seat61.com/interrail-and-eurail-reservations.htm

thanks a lot. I followed your link (italotreno.it) and the webpage even cannot find Chamonix, any advice? I have to use google search to figure out general route/time first for the day. Eurail.com cannot plan the route for me. Any other way to better plan route (like from GENOA TO CHAMONIX)?

I don't think ralderton linked .Italo's website. It's a high-speed train competitor against the state railways (Trenitalia).

For timetable purposes it's best to use bahn.com or DB Navigator app (German railways). They're both linked to the European-wide database so quite reliable !

Simply be aware that not all Italian regional trains timetables after 10th December have been released yet. Trenord/Trenitalia are always very late.

What's your travel date ? I could suggest an itinerary but it'll likely be the same as above via Switzerland.

Great. I plan to take train from Genoa ( after a cruise) to Chamonix with least transfer around noon on. jan1, 2024. I need to arrive at Chamonix on Jan 1. Using google, I got 4 or more transfers. Thanks for your advice.

I checked with bahn.com . It Provided better planning than Eurail.com and it also showed different transfer station than from google (Brig vs Visp). I guess that I need to wait for latest timetable. My other question is how I will know which train requires seat reservation. I assume that I have to check each train using bahn.com? Will bahn.com provide reservation for all trains in general? Thanks

In Italy trains listed as R or RV need no reservation. FR, IC EC do.

EC Italy - Switzerland requires reservation, All valid trains (except a few tourist specials) within Switzerland do not require reservation.

In France, TGV and IC require reservation, TER does not.

Thanks. I am starting from the basics.

Italotreno will book the train from Genoa to Milan, but not the train from Milan to Switzerland I think. 

Most folk on here use ÖBB (the option 2 listed on Seat61), which can sell both reservations.

You don’t need reservations after that. Just find an empty seat.

 It’s best to search for each train separately.

To clear up the confusion: Italo is a separate operator, and only offers very limited frequencies between Genoa and Milan (a few a week last time I checked), and Italo does not participate in Interrail/Eurail. With a pass, seat reservations for the Trenitalia services (interrail partner) can be made through italiarail and ÖBB, and I recommend the latter.

EC trains coming from Milan are regularly delayed (every day basically) so don't expect to take the 17:26 train from Brig. Fortunately there are 2 later alternatives :

- IR90 Brig - Martigny 17:57 - 18:47 or 18:26 - 19:14

- R Martigny - Vallorcine 19:18 - 20:05

- R Vallorcine - Chamonix 20:10 - 20:45

It is the last connection of the day so I'd play safe and leave Genoa at 12:19 instead of 13:19 so you're sure you don't miss the 15:20 EC. Have a coffee during your break :)

EDIT : the 15:20 EC train has only about 30 seats left, I wouldn't wait long before booking. IC trains from Genova have plenty of seats left.

Ah yes, I read the OP’s mention of Italo, and in my head I was thinking Italiarail!

Thanks to all for great advice. I now have APPS for DB, OBB, and Eurail planner. Eurail homepage still has more complete information including making seat reservation for my next trip. I also plan to use earlier train from Genoa to Milano. I made all seat reservations and the latest information is updated in the APP. I just need to print seat reservations before boarding the trains. Thanks again.