I have a PC and a laptop connected to the local network. Both have Ubuntu 18.04.4 Desktop, and both are visible to the modem:
But when I try to ping the laptop from the pc it says:
Destination Host Unreachable :
(base) marco@pc:~$ sudo ping 192.168.1.9 PING 192.168.1.9 (192.168.1.9) 56(84) bytes of data. From 192.168.1.7 icmp_seq=1 Destination Host Unreachable From 192.168.1.7 icmp_seq=2 Destination Host Unreachable
On the laptop there is no active firewall:
(base) marco@marco-U365G:~$ sudo ufw status Status: inactive
This is /etc/netplan/01-network-manager-all.yaml of the laptop:
network version: 2 renderer: NetworkManager # renderer: networkd ethernets: enp3s0: dhcp4: no addresses: (192.168.1.9/24) gateway4: 192.168.1.1 nameservers: addresses: (188.8.131.52,184.108.40.206)
I tried to use nmap from both pc and laptop:
(base) marco@pc:~$ sudo nmap -sn 192.168.1.0/24 Starting Nmap 7.60 ( https://nmap.org ) at 2021-05-06 18:28 CEST Nmap scan report for www.adsl.vf (192.168.1.1) Host is up (0.00045s latency). MAC Address: 74:36:6D:9A:5A:63 (Unknown) Nmap scan report for pc (192.168.1.7) Host is up. Nmap done: 256 IP addresses (2 hosts up) scanned in 3.77 seconds
And from the laptop:
(base) marco@marco-U365G:~$ nmap -sn 192.168.1.9/24 Starting Nmap 7.60 (https://nmap.org ) at 2021-05-06 18:29 CEST Nmap scan report for_gateway (192.168.1.1) Host is uo (0.00075s latency) Nmap scan report for marco-U365C (192.168.1.9) Host is uo (0.000054s latency) Nmap done: 256 IP addresses (2 hosts up) scanned in 3.21 seconds
I realized that this is happening, may be, since the router change by he Internet Service Provider.
How to solve the problem?