new droplet on private network cannot access other droplets

June 30, 2019 165 views
Networking Ubuntu 18.04

I had 3 droplets running with a private network setup. Recently I had to destroy and recreate one of the droplets. The new droplet cannot longer talk on the private network. Its eth1 interface seems completely shut off from the rest of the world.

To recreate the droplet I used the same command I had previously used:

docker-machine create --driver digitalocean --digitalocean-access-token $DIGITAL_OCEAN_TOKEN \
--digitalocean-image ubuntu-18-04-x64 --digitalocean-size s-4vcpu-8gb --digitalocean-region nyc3 \
--digitalocean-private-networking --digitalocean-monitoring \
--digitalocean-ssh-key-fingerprint MY_FINGERPRINT MY_HOST

I specifically checked the file /etc/netplan/50-cloud-init.yaml and it looked correct and I could see eth1 listed in there.

Any steps you can provide me on debugging this issue?

Thanks!

2 Answers

Hello!

As a quick bit of caution, private network settings will only work across Droplets in the same datacenter on the same account. With that in mind, let's dig in a bit more!

After taking a look over the 50-cloud-init.yaml file, one of the first things that I'd recommend checking is whether you see any issues when applying those same settings with the following Netplan commands:

sudo netplan generate
sudo netplan apply

If all is well, you can take a look at the active interfaces with ifconfig and make sure that eth1 is showing as UP and broadcasting the proper IP address and that the route is registering properly with your Droplet via route. There can also be a blocker configured in your firewall so I'd certainly recommend ensuring that only proper firewall rules are currently enabled:

sudo iptables -nvL --line-numbers

Should there be any further issues after verifying these things, it may be best to reach out to our Support team to get some specific details regarding your Droplet. Let me know if you have any other questions!

Great and thorough answer. Thank you.

Have another answer? Share your knowledge.