Why can't the virtual machine see the network through the NAT proxy?

Question

linux

I have a hypervisor that runs under ESXI and 1 external ip address that I can use for 1 virtual machine.

There are a lot of virtual machines, so it was decided to make 1 router vm with an external address, and connect the rest with a virtual local area network and proxy requests through nginx with router vm.

I did everything as described in wiki.hetzner.de/index.php/VMware_ESXi/ru , virtual machines see each other on 192.168, but the Internet sees only the router vm (the one with the external ip address).

Than it can be caused?

Answer 1

show with router-VM
# iptables -L -vn
# iptables -t nat -L -vn

Answer 2

I will add to @rostel
do virtual machines have a router vm gateway?
show on router vm
# cat /proc/sys/net/ipv4/ip_forward