Problems with dns access between singleuser pod

JupyterHub
1

I’m trying to give users access between servers within a namespace.
If everything works with external servers (hub, postgres, openssh-server), then how to get access from these servers to pod singleuser ?
Or get access from one user to another.

i started latest default config server with

singleuser:
  startTimeout: 30
  
  image:
    pullPolicy: Always
  
  cloudMetadata:
    blockWithIptables: false
  networkPolicy:
    egressAllowRules:
      privateIPs: true

nslookup

jovyan@jupyter-admin:~$ nslookup 
> hub
Server:         10.96.0.10
Address:        10.96.0.10#53

Name:   hub.jhub-dev.svc.cluster.local
Address: 10.105.59.121
> openssh-server
Server:         10.96.0.10
Address:        10.96.0.10#53

Name:   openssh-server.jhub-dev.svc.cluster.local
Address: 10.109.133.156
> jupyter-admin
Server:         10.96.0.10
Address:        10.96.0.10#53

** server can't find jupyter-admin: NXDOMAIN
>