Having trouble with the network on your droplet?

March 14, 2018 424 views
Networking

If you are having trouble reaching your droplet on the network, the cause could range from an older droplet booting into the wrong kernel to an actual network outage. We want to help you locate the cause of the problem, and we created this small article to speed up that process for you.

First, we want to be certain that this is not an issue with our platform. While we hope it isn't, we never want to dismiss the idea without checking. The best thing you can do to make sure that it is not an issue impacting others is to check our status page:

https://status.digitalocean.com

Just because it is not on the status page does not mean that it is not an issue with our platform. However, it can help us narrow down the possible causes if you join us in assuming for a moment that it may not be. There are some other things that we would like you to check. If you have opened a ticket with us about this, replying back with the information you have obtained from testing these things could help us to get a relevant answer to you with less delay.

1. Upstream issues

You can skip this one if the issue is with private networking.

It is entirely possible that an upstream provider between your ISP and our datacenter is experiencing an issue. You can help us rule this out by providing a traceroute and MTR to your droplet. The traceroute will help us see where the path ends, and the MTR will help us better understand if there is packet loss along that path. You can find instructions for performing these tasks here:

https://www.digitalocean.com/community/tutorials/how-to-use-traceroute-and-mtr-to-diagnose-network-issues

2. Network configuration

Your network configuration on the droplet may have been altered by accident, or by installing software that made modifications to it without your knowledge. Sometimes the changes that do this can sit dormant until your droplet reboots, which can present a scenario where you've not recently changed any settings, but perhaps a reboot caused old actions to take effect suddenly. You can find your correct network variables by clicking on your droplet at cloud.digitalocean.com, then clicking on Networking on the left-hand side. Let's focus first on the public network, and second on the private network. If you are not sure which one is relevant to you, the public network is most likely the correct answer.

Public Network:

You can edit your network configuration files to make sure they are correct. The most common locations for these files are here:

CentOS:

/etc/sysconfig/network-scripts/ifcfg-eth1

Debian / Ubuntu:

/etc/network/interfaces.d/50-cloud-init.cfg

To edit these files, you will need to use the console, by clicking on Access on the left-hand side of the droplet's page at cloud.digitalocean.com. If you are not familiar with editing files from the command line, this might help:

https://www.howtogeek.com/howto/42980/the-beginners-guide-to-nano-the-linux-command-line-text-editor/

If you have verified this information to be correct, performed a reboot on your droplet, and still have no network connectivity, providing the output of these commands in your support ticket may be helpful:

CentOS:

cat /etc/sysconfig/network-scripts/ifcfg-eth1
ip addr
ip route
iptables -nvL --line numbers

Debian / Ubuntu:

cat /etc/network/interfaces.d/50-cloud-init.cfg
ip addr
ip route
iptables -nvL --line numbers

Private Network:

Most of the time when we receive reports that private networking is not working, it is because the feature had been enabled on an existing droplet and not yet configured. Please note that private networking does not configure itself unless enabled during droplet creation. You can find instructions for its configuration on an existing droplet here:

https://www.digitalocean.com/community/tutorials/how-to-enable-digitalocean-private-networking-on-existing-droplets

3. Kernel

Networking can fail if you are running an older droplet which has a kernel selection box in the control panel. This selection box chooses the kernel that we try to boot, and just because the system boots does not mean that the correct one is selected. In this case, you will want to follow this guide to make sure you are booting under the right kernel:

https://www.digitalocean.com/community/tutorials/how-to-update-a-digitalocean-server-s-kernel

We hope that this information has been useful, or that it at least helps us to take care of your support ticket in a more timely manner.

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