I apologize, but I don't have enough specific information in the provided knowledge sources to give you a detailed answer about setting up a reverse proxy with Istio for your virtual service/gateway using Ory Oathkeeper. However, I can provide some general information about Ory Oathkeeper's reverse proxy functionality and a potential lead for Istio integration: Ory Oathkeeper can function as a reverse proxy. When started with the

oathkeeper serve

command, it exposes two ports: one for the reverse proxy and another for Oathkeeper's API [Ory Oathkeeper CLI documentation](https://www.ory.sh/docs/oathkeeper/cli/oathkeeper-serve). The reverse proxy port forwards requests to the upstream server defined in the rule if the request is allowed. If not allowed, Oathkeeper doesn't forward the request and returns an error message instead [Ory Oathkeeper Operating Modes](https://www.ory.sh/docs/oathkeeper#operating-modes). Regarding Istio integration, there is a mention of an "Ory Oathkeeper Istio best practices/reference configuration" in the community resources [Ory Community Resources](https://www.ory.sh/docs/ecosystem/community#ory-oathkeepeer). This might be a good starting point for integrating Oathkeeper with Istio, but I don't have access to the specific details of that configuration. For a more detailed and accurate answer on setting up Oathkeeper with Istio for your specific use case, I recommend consulting the official Ory documentation or reaching out to the Ory community forums.