SSH as service - more use cases

In previous post I described the most straightforward use case of SSH service usage: access VM at routable tenant private network.

The more interesting case could be to access a VM1_UUID that lays on not routable network: Tenant1 Subnet100
figure 1

Achieving SSH connectivity requires SSH gate (SSH jump host) to have a network interface on Tenant1 Subnet100. SSH service have to allocate neutron port on Tenant1 Subnet100 network and attach new port to SSH gate. Dynamic port attachment requires some underground SSH gate network configuration. SSH Service daemon can access SSH gate VM with SSH management key and update network configuration.
figure 2

Now traffic may flow to VM1_UUID even without router involvement. Authentication is performed gradually. We may use same concept of SSH configuration file with proxy command. 

figure 3

Generic SSH service

Both routable and no routeable VM connection schemes lays on boundary of specific tenant.

The more generic case of SSH service may take advantage of SOCKS.

SOCKS-based client establishes secure connection with SOCKS proxy
SOCKS Proxy:
  • Is an OSI level 5 tunneling active endpoint  
  • Establishes IP connection to remote peer on behalf of a client
  • Forwards traffic back and forth between the client and the server.
Why using SOCKS protocol?
  • Normally it is used as a secure internet access
  • Now enables secure service-on-demand multiplexing
The SOCKS reverse proxy, after authenticating the request, will forward it to the desired SSH jump host (via the Router that will also NAT the request)


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