AWS has recently announced the general availability of Amazon VPC Route Server. This new option simplifies dynamic routing in a VPC, allowing developers to advertise routing information via Border Gateway Protocol (BGP) from virtual appliances and dynamically update the VPC route tables associated with subnets and internet gateways.
Amazon VPC Route Server helps achieve routing fault tolerance for workloads running in subnets by dynamically updating VPC and internet gateway route tables with preferred routes. Route servers support VPC route tables not associated with subnets, subnet route tables, and internet gateway route tables.
Source: AWS documentation
The new option automatically updates route tables with routes learned from BGP peers, provides propagation of the best available routes based on BGP attributes, dynamically updates routes when network conditions change, and provides failover endpoints using BFD (Bidirectional Forwarding Detection). Matt Johnson, CTO at Rayo, comments:
This is highly relevant to public sector customers who are building out complex network architectures, and can help improve reliability when using EC2-based appliances. Worth checking out!
In a Reddit thread, most developers question the price of the new option. User itsalexjones writes:
The cost of that makes NAT Gateway look cheap.
User Mishoniko adds:
VPC Route Server costs US$540/mo (US$0.75/hr), so it better be worth it for your needs (…)Comparatively, NAT Gateway starts at $36/mo ($0.045/hr + $0.005/hr for IPv4 + $0.045/GB) and people constantly cry over how expensive it is. All a matter of perspective.
When a network device fails, the route server endpoints detect the failure through BFD configured on the route server peer. The endpoints then update the route server to withdraw routes from the Routing Information Base (RIB) and compute a Forwarding Information Base (FIB) from the RIB, selecting the best available routes. Finally, the route server updates the configured route tables with the routes from the FIB, and all new traffic is forwarded to the standby device. Corey Quinn, chief cloud economist at The Duckbill Group, recently covered BGP in his podcast and writes:
Ooh, if I learn BGP can I use it for things like alterNAT to smooth the route table transition between the NAT instance and the dread Managed NAT Gateway?
VPC Route Servers do not support route tables associated with virtual private gateways. The cloud provider recommends using Transit Gateway Connect to propagate routes into a transit gateway route table.
The new option supports both IPv4 and IPv6 route propagation and is available in a subset of AWS regions, including Northern Virginia, Ohio, Ireland, and Tokyo. Pricing varies by region and starts at 0.75 USD per VPC Route Server endpoint per hour.
