a.p., My situation looks as:
1) There is host esxi server Inside my LAN. (192.169.3.105)
2) There are guest OSs, including UbuntuServer (192.168.3.101)
3) Cloud Storage installed on Ubuntu (ownCloud) and listen 443 port.
4) My router forward TCP/UDP traffic from external IP adress (x.x.x.x:443) to UbuntuServer (192.168.3.101:443)
5) Also, I need to connect to esxi host from the outside, of course, I connect through router, using external IP adress ( x.x.x.x),
but in this case, router needs to forward traffic to host OS (192.169.3.105). but rule of forwarding for 443 port is busy.
Perhaps, it is possible to change port for ownCloud clients, but they are installed more than that on 30 PCs
and not comfortable for users, who prefer access to CloudStorage via web-browser.