This is preliminary question, and searching "mailstones" and comments. I read manual, faq etc.
First: I want use Openwrt as standard router. "Black box, RJ-connector named WAN, RJ-connector named LAN". WAN, ISP use dynamic ip (general 4G-modem with rj-"output"). LAN, normal dhcp, nat, etc. Just normal functions, this all is possible make using any bulk router. But... Openvpn, ssh... it will be goal. Now I am on chalclines.
Hardware, first I think use any router. Then, Rasp. But: I have many computer with i7-processor, SSD and Openwrt-compatible LAN-card. ("Many", long story...) Then, I have a couple of HP Procurve switches. So, all what I need is here.
More prology: Now I use old Cisco ADSL-router. In this model it is not possible use ETH-port as WAN. Only WAN is adsl. But, easy as 1-2-3: CLI is most easy way configure this type devices. So: "VLAN 100, name OWN-WAN, interface eth-0, ip = dhcp + some adjust", "VLAN 123, name LAN, interface eth1, 2, 3, nat, dhcp etc". So: I program it Cisco "eth 0 = WAN, other eth = lan". In nutcell. Why I say this, later.
Some basic, really basic question need clarification.
QUESTION 1: So, I use x86-computer as router. It is normal computer with one LAN-port. Must I add second LAN-card for second port? "WAN" and "LAN"
QUESTION 2: IF I can use only one network card, it mean "LAN and WAN" is same hole. So I must add this HP Procurve switch and program it. Is this possible? I am not sure of "how to". I read it article VLAN, but not sure understand or not. Maybe it is same as my example of Cisco. Maybe it is "Procurve switch ETH1 = connection to router, LAN+WAN". ETH2 = WAN, hole to bad world. Maybe it is , eth1 = trunk, Eth2 = VLAN 1000 . All other port eg. VLAN 2. Maybe any this type configuration works? Any physical ethernet port is connection to WAN, to bad world and this port is VLAN 1000. So, if ETH 1 = router = trunk, this ETH2 (VLAN 1000) is "connected" to eth1. Then Openwrt-configuration is "LAN, it is VLAN 2".
So: If I am right, I can use only one "hole" router? Any comments, ideas?