About linux : telnet-Unable-to-connect-to-remote-host-No-route-to-host—with-docker-installed

Before to run sudo apt install -y docker-ce I was able to run telnet without issues in my machine, but when I install that package I’m not able to run telnet successfully.

Before installing docker-ce

telnet 172.10.11.124 1521
Trying 172.10.11.124...
Connected to 172.10.11.124.

After installing docker-ce

telnet 172.10.11.124 1521
Trying 172.10.11.124...
telnet: Unable to connect to remote host: No route to host

If I uninstall docker, Telnet runs without problems.

Can anyone help me how can I solve this problem with docker-ce installed?

Obviously, it’s a network layer conflict with IPv4. You cannot connect to the mentioned IP because after you installed the Docker, it will create a virtual network.
To fix this issue, you must remove/change the Docker network. At first, inspect the networks by:

docker network ls

Then, after you’ll get the list of networks, try to find the related network:

docker network inspect <network-id>

Finally, you can rm or reconfigure the Docker’s virtual network as well.