AWS Transit Gateway Site-to-Site VPN Dynamic routes limit of 100. Is it per Connection or Aggregate?
Is the dynamic routes advertised from a customer gateway device to a Site-to-Site VPN connection on a Transit Gateway (TGW) limit of 100 per attachment or aggregate?
What happens if there are multiple VPN attachments to the same TGW? Say I have a VPN to the TGW and I’m learning 75 routes there from propagation, and then another VPN attached to the TGW with another 75 routes advertised there. Will that have any issues, since it will be 150 routes learned to the TGW? Is the total aggregate to the TGW or per connection and then limited to the total 10,000 total routes per TGW?
The 100 routes from on-premises is per VPN attachment and can scale out with multiple VPN attachments. We'd typically recommend route summarization or using a default route for situations where a customer wants to advertise over 100 routes. If neither of those options will work, the customer can use multiple VPN attachments and splitting the routes. The 10,000 route limit is the total per TGW. Another thing to look out for here is that you can advertise up to 1,000 routes to on-premises through VPN. Make sure you don't have more routes than that in the TGW route table, as the max routes advertised from a Site-to-Site VPN connection on a TGW to a customer gateway device: 1,000
Relevant questions
If only one of the tunnels of site to site vpn is down, is communication possible?
Accepted Answerasked 2 months agoHow can I make a third-party cloud vpn connection?
asked 2 months agoAWS Network Firewall and VPN Gateway
asked 10 days agoAWS Transit Gateway Routing Features
Accepted Answerasked 3 years agoTransit Gateway - number of prefixes from TGW->CGW
Accepted Answerasked 3 years agoIs it possible to set up a dynamic routing connection to AWS through a site-to-site VPN via a vendor?
Accepted Answerasked 2 years agoTransit Gateway - Propagated route limit per Routing Table
Accepted Answerasked 3 years agoControling BGP Route Propagation in Transit Gateway
Accepted Answerasked 2 years agoAWS Transit Gateway Site-to-Site VPN Dynamic routes limit of 100. Is it per Connection or Aggregate?
Accepted AnswerTransit Gateway connection from customer gateway using Palo Alto without BGP
Accepted Answerasked 3 years ago