Does nomad have a generic TCP/UDP load balancer (i.e. non HTTP) for inbound traffic? Something based on IPVS (akin to Kube-Router) would be ideal for the use-cases where Nomad would make sense for me.
Not builtin. We recommend folks run their load balancer in Nomad. Traefik is a common solution here as it already supports Nomad's service discovery. Other solutions often use templating and sig-hupping to configure: https://www.nomadproject.io/docs/job-specification/template
Nomad also supports CNI. It's not uncommon for folks to run their network's control plane as a Nomad job and use a CNI plugin to integrate their other Nomad jobs with it. This sort of approach allows for running multiple logical networks within a single Nomad cluster (eg perhaps segments of your cluster use a service mesh while data intensive or legacy applications use host networking).