Re: Open VPN networking is working but no internet access

The default gateway should be in the same L2 domain (must have an interface with an ip address which belongs to the same network as the hosts).
In your case, if your openvpn server address is 192.168.100.1, then this is the default gateway for reach remote networks (when connected in VPN, from your host's viewpoint, the 192.168.1.0/24 network is a remote network, and is reacheable via 192.168.100.1, while the 192.168.100.0/24, as well as 192.168.30.0/24, are instead locally connected networks)
Set the correct ip address (192.168.100.1) in the vpn option.
Generally speaking, for the network addresses, is never a good idea use 192.168.0.0/xx or 192.168.1.0/xx, these are the most commonly used network addresses, and if you are connected to the wifi, for eg. in a bar or restaurant, which uses one these network address,es you won't be able to reach your 192.168.1.0 network via vpn, since your pc will see this network as locally connected (with a lower metric)
Cheers,
jonatha