Question

Server on kubernetes not responding to UDP calls.

We have encountered an issue with running a relay server that processes UDP calls on DigitalOcean Kubernetes cluster. Even with fully open inbound UDP port range allowing all UDP traffic to go trough firewall, the server still doesn’t seem to respond when pinged.

The k8’s deployment is configured to use host network.

I listed the added firewall rules below.

  [...]
  inbound_rule {
    protocol         = "udp"
    port_range       = "1-65535"
    source_addresses = ["0.0.0.0/0", "::/0"]
  }

  outbound_rule {
    protocol              = "udp"
    port_range            = "1-65535"
    destination_addresses = ["0.0.0.0/0", "::/0"]
  }

  outbound_rule {
    protocol              = "tcp"
    port_range            = "1-65535"
    destination_addresses = ["0.0.0.0/0", "::/0"]
  }

  outbound_rule {
    protocol              = "icmp"
    port_range            = "1-65535"
    destination_addresses = ["0.0.0.0/0", "::/0"]
  }
  [...]

A note: The server works without issues when deployed as a simple docker container without Kubernetes, that leads us to think that the issue could be related Kubernetes, but we haven’t found a specific explanation for that yet.

Show comments

Submit an answer

This textbox defaults to using Markdown to format your answer.

You can type !ref in this text area to quickly search our full set of tutorials, documentation & marketplace offerings and insert the link!

Sign In or Sign Up to Answer

These answers are provided by our Community. If you find them useful, show some love by clicking the heart. If you run into issues leave a comment, or add your own answer to help others.

was there any answer to this? I have a similar/same problem: need to use host networking in one of my node pools and open a range of ports to the internet. (I’m doing VoIP, notoriously difficult in Kubernetes)

This comment has been deleted