Hosts are not visible from the outside

Question

Computer networks

Hello everyone,

Given a lab network with multiple hosts that I go to from my work machine. So, it turned out that two hosts from this laboratory network are not available from my workplace, but are available if I first log in to any available host from the laboratory network. All hosts are on the same network and connected to the same switch. What could be the matter here, in which direction to dig?

Answer 1

If you described what kind of authorization, then you could suggest more options,
And it looks like a guest vlan

Answer 2

default route is not registered by machines of those?

Answer 3

Let's go in order!
What OS is on two hosts that are not available
What switch is in the center
which means it is not available? pings pass?

Answer 4

Offhand
1. Check the settings of active network switches, router - vlans, subnets, routing should be the same on all hosts and pieces of iron.
2. Check the settings of the firewall, ssh, daemon on specific servers, where it allows you and does not let you.
3. Check the settings of blockers after several incorrect attempts to enter a password and apparmor, or that you have such a distribution in your distribution
. Something else most likely