VPN Tunneling Encapsulation Questions?
I was hoping someone might be able to clear up a few questions I have re: VPN & tunneling protocols. The TechExam notes says PPTP encapsulates PPP. When referring to VPNs, is it just assumed that PPP is present & is encapsulated (by PPTP or L2TP for example)? Would this be an accurate example of how encapsulated layers might look over a VPN? 1)IPX is the first encapsulated protocol, 2)PPP wraps around IPX, 3) L2TP & IPSEC combined wrap around PPP, 4) IP encapsulates the first three layers & acts as the carrier protocol? I get the impression that IPSEC isn't really a tunneling protocol & doesn't encapsulate PPTP or L2TP. Instead, it just enhances PPTP/L2TP security (i.e. you couldn' use only PPP & IPSEC, right)?