How to use VPN with a VPC hub-and-spoke architecture

Website-to-site Virtual Private Network (VPN) has been used to attach distributed networks for many years. This publish describes learn how to use a VPC VPN Gateway to attach an on-premises (enterprise) community to the IBM Cloud VPC in a transit hub-and-spoke structure:

Every spoke could be operated by a unique enterprise unit or group. The group can enable enterprise entry to VPC sources like Digital Service Cases working functions or VPC RedHat OpenShift IBM Cloud clusters. Personal enterprise entry to VPE-enabled services, like databases, can be doable by the VPN gateway. With this technique, you may benefit from the ease of use and elasticity of cloud sources and pay for simply what you want by accessing the sources securely over VPN.

The Centralize communication through a VPC Transit Hub and Spoke architecture tutorial was revealed just a few months in the past. The companion GitHub repository was modified to optionally assist a policy-mode VPC VPN gateway to switch the IBM Direct Link simulation.

Multi-zone area (MZR) design

The transit hub design integrates with IBM multi-zone areas (MZRs), and the VPN Gateways are zone-specific. After some cautious examine, the zonal structure proven under was carried out. It exhibits solely two zones however could be expanded to 3:

Notes:

1. A VPN Gateway is related to every zone. Enterprise CIDR blocks are related to a selected cloud zone VPN Gateway. Discover the enterprise CIDR block is slender:192.168.0.0/24. The cloud CIDR block is broad, overlaying your complete cloud (all VPCs and all zones): 10.0.0.0/8.
2. A VPC Deal with Prefix representing the enterprise zone is added to the transit VPC. See how phantom address prefix enable the spokes to route visitors to the enterprise within the tutorial.
3. A VPC ingress route desk is added to the transit VPC as described on this example. It’ll routinely route all ingress visitors from the spokes heading to the enterprise by the VPN gateway home equipment.

Observe the steps within the companion GitHub repository within the TLDR part. When modifying the config_tf/terraform.tfvars file, be certain that the next variables are configured:

config_tf/terraform.tfvars:

enterprise_phantom_address_prefixes_in_transit = true
vpn = true
firewall = false

Additionally think about setting make_redis = true to permit provisioning Redis situations for the transit and spoke with related Virtual Private Endpoint Gateway connections. If configured, even the personal Redis occasion within the spoke could be accessed from the enterprise. The small print of personal DNS configuration and forwarding are lined in this section of part 2 of the tutorial.

When all the layers have been utilized, run the exams (see particular notes within the GitHub repository README.md on configuring Python if wanted). All of the exams ought to go:

python set up -r necessities.txt
pytest

A word on enterprise-to-transit cross-zone routing

The preliminary design labored effectively for enterprise <> spokes. The enterprise <> transit inside the similar zone additionally labored. However extra configuration is required to resolve enterprise <> transit cross-zone routing failures:

With out the extra cross-zone VPN Gateway Connections, there have been no return VPC route desk entries within the default route desk within the transit VPC to the cross-zone enterprise (see the pink line). The VPN Gateway Connections routinely add routes to the default route desk within the transit VPC however solely within the zones containing the VPN Gateway. Within the diagram above, the employee 10.2.0.4 had no path to return to 192.168.0.4.

The additional cross-zone connections for the transit VPC zones resolved this situation, as proven by the blue line.

Conclusions

Website-to-site VPN could be simply the expertise you could join your enterprise to the IBM Cloud VPC in a multi-zone area. Utilizing the steps described on this publish, you may reduce the variety of VPN Gateways required to totally join the enterprise to the cloud. Benefit from the personal connectivity to VPC sources like Digital Server Cases and sources from the catalog that may be accessed by a Digital Personal Endpoint Gateway.

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