Hi @rodrigo rb,
Welcome to Microsoft Q&A Platform. Thank you for reaching out & hope you are doing well.
Answering your queries,
- You can deploy an Azure Firewall in vnet-B and point traffic from vnet-C to vnet-B and from vnet-B it will go to vnet-A.
- From vnet-A, add a UDR and point it to azure firewall in vnet-B.
- This way the firewall will act as an interface sending the traffic between both sides.
- Regarding NVA loopback, as we don't deal with it, please contact your vendor, they might help you with it.
Kindly let us know if the above helps or you need further assistance on this issue.
If so, I would appreciate it if you could accept the response as a "Accept Answer" and "Upvote it" so that it can help other members of the community who may be experiencing similar challenges.
Thanks,
Sai Prasanna.