Ubuntu local IP address does not resolve

Question

I set a Hugo web server, which listen on localhost:30000. The ubuntu machine has the 192.168.2.137 address.

When i do:

curl http://localhost:30000/ -> OK
curl http://127.0.0.1:30000/ -> OK

but,

curl http://192.168.2.137:30000/ -> curl: (7) Failed to connect to 192.168.2.131 port 30000: Connection refused

What could be the reason for that?

My /etc/netplan/00-installer-config.yaml looks like:

network:
version: 2
renderer: NetworkManager
ethernets:
  enp0s3:
    dhcp4: false
    addresses: [192.168.2.137/24]
    gateway4: 192.168.2.1
    nameservers:
      addresses:
        - 8.8.8.8
  lo:
    renderer: networkd
    match:
      name: lo
    addresses:
      - 192.168.2.137/24

I also add an entry to /etc/hosts:

192.168.2.137 localhost

Answer 1

You said that it's listen on localhost so if you use other interface it won't work which is normal. You should listen on all interfaces or listen to the interface enp0s3.