What changes are required to enable communication with the external vendor?
Create an IPv6 NAT instance. Add a route for destination 0.0.0.0/0 pointing to the NAT instance.
Enable IPv6 on the NAT gateway. Add a route for destination ::/0 pointing to the NAT gateway.
Enable IPv6 on the internet gateway. Add a route for destination 0.0.0.0/0 pointing to the IGW.
Create an egress-only internet gateway. Add a route for destination ::/0 pointing to the gateway.
Explanations:
An IPv6 NAT instance is not required. NAT instances are primarily used for IPv4. Adding a route for 0.0.0.0/0 is irrelevant for IPv6 communications.
NAT gateways do not support IPv6. Therefore, enabling IPv6 on a NAT gateway and adding a route for ::/0 is not applicable.
While enabling IPv6 on an internet gateway is necessary for IPv6 traffic, adding a route for 0.0.0.0/0 is intended for IPv4, not IPv6.
An egress-only internet gateway allows outbound IPv6 traffic while preventing unsolicited inbound traffic. Adding a route for ::/0 pointing to the egress-only internet gateway is necessary for enabling outbound communication to the external vendor over IPv6.