I'm using Consul to create a service-mesh, it's all working well.
I want to send traffic to an IP/host not managed by the mesh, which doesn't have a side car.
Is this possible, I don't think it is?
Consul provides native support for connecting to egress services through proxies called terminating gateways. The destination service only needs to be registered into the service catalog, and the mesh configured to route connections to that service through the gateway.
The Understand Terminating Gateways tutorial provides a bit more in-depth information on the supported deployment patterns. It also links to a subsequent tutorial, Connect External Services to Consul With Terminating Gateways, which walks through the process of configuring and connecting to external services from within the mesh.