Ubuntu Server 18.04 Destination Host Unreachable

I installed Ubuntu Server 18.04 and configured the network:

network: version: 2 renderer: networkd ethernets: enp3s0: dhcp4: no addresses: - 192.168.95.227/24 gateway4: 192.168.95.1 nameservers: addresses: [8.8.8.8, 8.8.4.4]

The router is a Cisco with DHCP disabled, everything is working fine, all other 50+ computers connecting to the internet, so not a problem with the router/gateway.

Now when I ping 192.168.95.1 or any other IP with a working computer its working, but when I ping any external IP like 8.8.8.8 I get Destination Host Unreachable

Now the Server is locally connected within the network, but no internet access.

Any suggestions?

2 Answers

I personally don't think this error lies within the Ubuntu System. Can you check on your Cisco router if the ICMP packages arrive there and are routed correctly?

You should check if your router blocks icmp or more for your specific IP address.

You should also check if you have given the 192.168.95.227 address to two different devices.

You can check that with a ping to the .227 and shutting down the Server. When the ping still answers, you have two clients with the same IP.

.yaml

Set your .yaml to the following, keeping the indentation, and no tabs:

network: version: 2 renderer: networkd ethernets: enp3s0: addresses: [192.168.95.227/24] gateway4: 192.168.95.1 nameservers: addresses: [8.8.8.8, 8.8.4.4]

sudo netplan --debug generate

sudo netplan apply

reboot # you must reboot

ethernet cabling

The ethernet interface is only running at 100Mb, and this usually means a cabling problem. Assure that you are using quality cat 5e or cat 6, or better, cabling. Reverify 1000Mb operation by viewing the sudo lshw -C network command, and observe the SIZE/speed parameter.

Verify that all network hardware, switches/hubs/router/etc, are gigabit capable and functioning correctly.