With what help to organize the server of the centralized access?

Question

SSH

There are a lot of irons. Some only support ssh, some only telnet, some only http.
In my head it looks like this:
Client => some piece of hardware that has access to web/telnet/ssh => web/telnet/ssh itself

There are a few more questions:
1) Is it possible to secure http? (Exactly http, because https is not supported by the switch)
2) Is it possible to secure telnet?
3) How to organize a central access server?

Answer 1

There is such a product - Hashicorp Boundary .
Acts as a proxy for connections. Theoretically, it can authorize a connection over any TCP protocol.
To work, it will require you to use your client to establish connections and perform user authorization.

Answer 2

You can only secure HTTP and Telnet by securing the channel. For example, using VLAN.

Answer 3

The management is pushed into a separate VLAN, then a server is installed (usually on Linux), from which the management (and up to the heap and monitoring) of all junk is already taking place.
Moreover, even if the hardware supports HTTPS, you should not expose the control port to the Internet, due to
- backdoors of the hardware manufacturer
- holes in the admin
panel - lack of adequate protection against password brute force.

Answer 4

1) Is it possible to secure http? (Exactly http, because https is not supported by the switch)

Yes.

2) Is it possible to secure telnet?

Yes.

3) How to organize a central access server?

Server on GNU/Linux as Jump host (actually, as you describe in the question Client => some piece of hardware that has access to web/telnet/ssh => web/telnet/ssh itself ) and some SSH.
Food for Thought:
The Magic of SSH
A Reminder for ssh Users
PS
Maybe you'll need tinc somehow
Or trendy WireGuard