virtualbox ping, telnet works but not curl

Question

I am using cuckoo sandbox for malware analysis. I have a virtualbox vm which has the IP set to 192.168.56.101. When the vm is powered on, there is a script agent.py which listens on port 8000. The network is host-only configuration on the virtualbox side. The host-only adapter has the IP set to 192.168.56.1

When the VM is in power on state,

the guest(192.168.56.101) is able to ping host (192.168.56.1)

the host(192.168.56.1) is able to ping the guest (192.168.56.101).

Telnet works for the host IP(192.168.56.101) at the Port(8000).

When I try curl it fails and I'm responded with the error message

ERROR: The requested url could not be retrieved.

However when I enter the same IP and port combination, I'm greeted with the success message instead of the error.

I'm in a university network and hence need to use proxy. I feel the proxy is the culprit and hence tried to disable it by unsetting it at the command line but for no success.

What could be the reason for this? Proxy or any other settings internally? Posting the screenshots for reference.

Answer 1

In fact, the curl is working correctly. Look at the answer: curl worked without errors, but the answer came from you, with an error from Squid "The requested URL could not be retrieved". Therefore, I believe that the reason in the proxy server