Internal network with Netplan in Ubuntu 21.04

I'm trying to implement a simple internal network (client - router - server) in Ubuntu 21.04 on VirtualBox.

I'm new to Netplan and I have the configuration for Ubuntu previous releases (16.04) with the old /etc/network/interfaces file.

here is the old configurations :

Client :

# The internal interface on neta
auto enp0s8
iface enp0s8 inet static
    address 192.168.1.11
    netmask 255.255.255.0
    network 192.168.1.0
    broadcast 192.168.1.255
    post-up route add -net 192.168.0.0 netmask 255.255.0.0 gw 192.168.1.1 dev enp0s8
    pre-down route del -net 192.168.0.0 netmask 255.255.0.0 gw 192.168.1.1 dev enp0s8

Router :

# The internal interface on neta
auto enp0s8
iface enp0s8 inet static
    address 192.168.1.1
    netmask 255.255.255.0
    network 192.168.1.0
    broadcast 192.168.1.255

# The internal interface on netb
auto enp0s9
iface enp0s9 inet static
    address 192.168.2.2
    netmask 255.255.255.0
    network 192.168.2.0
    broadcast 192.168.2.255

Server :

# The internal interface on netb
auto enp0s8
iface enp0s8 inet static
    address 192.168.2.22
    netmask 255.255.255.0
    network 192.168.2.0
    broadcast 192.168.2.255
    post-up route add -net 192.168.0.0 netmask 255.255.0.0 gw 192.168.2.2 dev enp0s8
    pre-down route del -net 192.168.0.0 netmask 255.255.0.0 gw 192.168.2.2 dev enp0s8

I tried to configure the Server, and here is what I did with Netplan :

network:
version: 2
renderer: NetworkManager
ethernets:
 enp0s8:
  dhcp4: no
  addresses:
  - 192.168.2.22/24
  gateway4: 192.168.2.2
  nameservers:
   addresses: [8.8.8.8, 8.8.4.4]

• Is my config equivalent to the old one (without specifying netmask, network, broadcast etc..) ?
• For nameservers I did what I saw in a tutorial (8.8.8.8, 8.8.4.4), is it correct in my case ?
• For the Router config in Netplan, do I need a gateway address ? same thing with nameservers ?

Thanks