The need for site to site VPN

[Martorossi]

If you have Three Routers

R1(192.168.1.1)-----------------(192.168.1.2)R2(192.168.2.1)--------------(192.168.2.2)R3

Connected in this sequence and there is a routing protocol of Eigrp running on all three routers advertising all links hence R1 can ping R3 why would you establish a Site to Site VPN Connection Between R1(192.168.1.1) and R3(192.168.2.2) since R1 can already ping R3 due to EIGRP routing protocol.

[Nagendra Kumar Nainar]

Hi,

You dont normally see VPN between nodes that are completely connected via nodes that belong to same organization. In your example above R1, R2 and R3 are enabled with EIGRP (assumng it under same admin domain). So you dont need VPN here.

Assume R1 and R3 belongs to your domain and R2 (or R2-R22-R222) belong s to a different provider. You need to secure your traffic by encrypting and may need to run a different protocol between your nodes and provider domain nodes. In such case, you need VPN.

Hope this clarifies.

Nagendra