Cloud to on-premise port forwarding with IP address bound to loopback alias
An example method to provide communication between a first computer in a first computer network and a second computer in a second computer network is disclosed. The method includes aliasing the second computer's address in the second computer network to a loopback interface of a third computer in the first computer network and establishing a tunnel between the third computer and a fourth computer in the second computer network. Establishing the tunnel includes configuring the fourth computer to forward traffic received from the tunnel to the second computer. The method further includes configuring routing in the first computer network to direct traffic destined for the second computer network to the third computer, and configuring the first computer to transmit packets destined for the second computer with the second computer's address in the second computer network.
1. A method to provide communication between a first computer in a first computer network and a second computer in a second computer network, the first computer network corresponding to at least part of a public cloud, comprising:
aliasing the second computer's address in the second computer network to a loopback interface of a third computer in the first computer network, wherein the second computer network corresponds to a private cloud protected by a firewall;
establishing a tunnel between the third computer and a fourth computer in the second computer network, wherein establishing the tunnel includes configuring the fourth computer to forward traffic received from the tunnel to the second computer;
configuring routing in the first computer network to direct traffic destined for the second computer network to the third computer; and
configuring the first computer to transmit packets destined for the second computer with the second computer's address in the second computer network.
2. The method of claim 1 , further comprising:
the first computer transmits a packet with the second computer's address in the second computer network;
the third computer receives the packet and sends the packet, via the loopback interface, to the tunnel; and
the fourth computer receives the packet from the tunnel and forwards the packet to the second computer.
3. The method of claim 1 , further comprising providing the second computer's address in the second computer network to the first computer.
4. The method of claim 1 , wherein the tunnel comprises a secure shell (SSH) tunnel, the third computer comprises a SSH server, the fourth computer comprises a SSH client.
5. The method of claim 1 , wherein the first computer network comprises a virtual private cloud in the public cloud.
6. The method of claim 1 , wherein the first computer, the second computer, the third computer, and the fourth computer are physical computers, virtual machines on physical host computers, or a combination of physical computers and virtual machines.
7. The method of claim 1 , wherein configuring routing in the first computer network comprising configuring a routing table of a router in the first computer network.
8. A non-transitory, computer-readable storage medium encoded with instructions executable by a processor to provide communication between a first computer in a first computer network and a second compute in a second computer, the first computer network corresponding to at least part of a public cloud, the instructions comprising:
aliasing the second computer's address in the second computer network to a loopback interface of a third computer in the first computer network, wherein the second computer network corresponds to a private cloud protected by a firewall;
establishing a tunnel between the third computer and a fourth computer in the second computer network, wherein establishing the tunnel includes configuring the fourth computer to forward traffic received from the tunnel to the second computer;
configuring routing in the first computer network to direct traffic destined for the second computer network to the third computer; and
configuring the first computer to transmit packets destined for the second computer with the second computer's address in the second computer network.
9. The storage medium of claim 8 , wherein the instructions further comprises:
the first computer transmits a packet with the second computer's address in the second computer network;
the third computer receives the packet and sends the packet, via the loopback interface, to the tunnel; and
the fourth computer receives the packet from the tunnel and forwards the packet to the second computer.
10. The storage medium of claim 8 , wherein the instructions further comprises providing the second computer's address in the second computer network to the first computer.
11. The storage medium of claim 8 , wherein the tunnel comprises a secure shell (SSH) tunnel, the third computer comprises a SSH server, the fourth computer comprises a SSH client.
12. The storage medium of claim 8 , wherein the first computer network comprises a virtual private cloud in the public cloud.
13. The storage medium of claim 8 , wherein the first computer, the second computer, the third computer, and the fourth computer are physical computers, virtual machines on physical host computers, or a combination of physical computers and virtual machines.
14. The storage medium of claim 8 , wherein configuring routing in the first computer network comprising configuring a routing table of a router in the first computer network.
15. A system for communication between a first computer in a first computer network and a second computer in a second computer network, the first computer network corresponding to at least part of a public cloud, comprising:
the first computer network, comprising:
the first computer configured to transmit packets destined for the second computer with the second computer's address in the second computer network, wherein the second computer network corresponds to a private cloud protected by a firewall;
a third computer configured with the second computer's address in the second computer network aliased on a loopback interface of the third computer; and
a router configured to direct traffic destined for the second computer network to the third computer; and
the second computer network comprising:
the second computer; and
a fourth configured with a tunnel to the third computer and to forward traffic received from to the tunnel second computer.
16. The system of claim 15 , wherein:
the first computer transmits a packet with the second computer's address in the second computer network;
the router directs the packet to the third computer;
the third computer sends the packet, via the loopback interface, to the tunnel; and
the fourth computer receives the packet from the tunnel and forwards the packet to the second computer.
17. The system of claim 15 , further comprising a fifth computer configured to receive the second machine's address from the second computer network and send the second computer's address to the first computer network.
18. The system of claim 15 , wherein the tunnel comprises a secure shell (SSH) tunnel, the third computer comprises a SSH server, the fourth computer comprises a SSH client.
19. The system of claim 15 , wherein the first computer network comprises a virtual private cloud in the public cloud.
20. The system of claim 15 , wherein the first computer, the second computer, the third computer, and the fourth computer are physical computers, virtual machines on physical host computers, or a combination of physical computers and virtual machines.