Hello, when you connect to a VPN via your PC client, often your computer's route table gets populated with all the routes that are part of that VPN connection. I am just wondering what the mechanism is that populates your route table i.e. is it the VPN client that does it, or is it some protocol from a server on the VPN etc. ? Thanks for any info.
Hi, many clients like the Cisco and sonicwall VPN clients install addional network adaptrers on the client machine. Its these that when the VPN connection is established inject routes into the route table as directly connected networks in the case of split tunnels or as a default route for tunnel all mode connections.
They are provided as part of the phase 2 negotiations normally by the remote gateway/firewall. Phase 1 is normally basic authentication such as IP address and psk etc. But many VPNs require the client to already have this information. Normally a network admin would distribute this configuration to the machines.
Its this hastle of configuration that's made SSL VPNs popular and the client and it's configuration are destribuated via a hosted web portal. If the admin changes the secured networks no reconfiguration is needed to the client machines, they just login to the portal and get the new settings.