How to open some ports on Ubuntu?
I know little about Linux.Today I create a VPN server on My ubuntu according to https://github.com/philplckthun/setup-simple-ipsec-l2tp-vpn But when I finish the installation. I use my iphone to connect the ipsect vpn,bur it shows the VPN Server has no response. The github document shows Ports 1701, 500 and 4500 must be opened for the VPN to work! So … Read more