it happens when you have dynamic ip on your ubuntu server and suddenly your ip has changed and you have problems connecting with your local services because of ip change. here the solution
sudo apt-get install network-manager
Networking is handled by netplan by default in Ubuntu Server 18. I suggest that you edit the /etc/netplan/01-netcfg.yaml file to read:
nano /etc/netplan/01-netcfg.yaml
and add the next and modify the ip according to your local ip. In my case, my ip was going to be 192.168.0.10
# For more information, see netplan(5).
network:
version: 2
renderer: networkd
ethernets:
ens33:
dhcp4: no
dhcp6: no
addresses: [192.168.0.10/24]
gateway4: 192.168.0.1
nameservers:
addresses: [190.113.220.18,192.113.220.51]
Exit and save your changes by running the command:
sudo netplan apply
Please note and follow the spacing and indentation. then restart network
service network-manager restart
Comment out all the ens33 stanzas in /etc/network/interfaces. Reboot.
reboot
