AWS VPN Client on Linux Ubuntu not working

Hi, I understand that you are facing connectivity issues for your VPN on Ubuntu. The following are some troubleshooting steps that you can take to determine the source of your issue:

Since your client is already connecting, you do not need to check your VPN client configuration for Ubuntu with credentials, encryption, and server address.

1. Check DNSTry using netcat on port 53 (the standard port for DNS) to the DNS server.

Since telnet and curl doesn’t work, you should try using ping to test if basic connectivity exists. The command to do so would be “ping 8.8.8.8” or “ping amazon.com”. If this works, try to use the “dig amazon.com” command to trace and determine whether the port is open. Ping will tell you if the ICMP port is open, while dig will tell you more information on the DNS resolvers.

If this doesn’t work, you might be having internet connectivity problems. In this case, follow the steps provided in the section “Clients can’t access a peered VPC, Amazon S3, or the internet” at https://docs.aws.amazon.com/vpn/latest/clientvpn-admin/troubleshooting.html.

2. If this does work, check your /etc/resolv.conf file for the proper DNS servers. You can manually add them if needed and then check DNS resolvability with nslookup example.com.

Check VPN Routes: Check that there are routes for your VPN subnet in the route table and properly routed to the internet gateway. You can also use “ip route” to check this.

3. Check server side Firewalls and Security Groups: You should check your firewall configurations to see if it’s blocking traffic that you want.

4. Verify Split Tunneling Setup: a. Ensure that your configurations for Split Tunneling is correct. b. Here are some links for proper setup of your VPC endpoint split tunnels: i. Main setup instructions: https://docs.aws.amazon.com/vpn/latest/clientvpn-admin/split-tunnel-vpn.html ii. More detailed instructions: https://docs.aws.amazon.com/vpn/latest/clientvpn-admin/cvpn-working-endpoints.html#cvpn-working-endpoint-create

Your VPN logs might also be a helpful clue to resolving your problem and can be found in /var/log/. For more information and a more detailed guide on troubleshooting your VPN Client, see https://docs.aws.amazon.com/vpn/latest/clientvpn-admin/troubleshooting.html.

Please let me know if you have any further questions. Hope this helps!