Misha Bragin
Co-founder and Contributor at NetBird
About
Misha Bragin is a software engineer, open source contributor, and co-founder of NetBird - an open source, zero-trust networking platform built on WireGuard. As a member of the Cloud Native Computing Foundation, Misha and the NetBird team are on a mission to make secure private networking and remote access ridiculously simple for everyone, from home users to large enterprises.
Presentation
Hijacking DNS Port 53 with eBPF & XDP for Remote K8s Access
Have you tried running a local DNS resolver on a non-standard port? Changing port 53 is tricky since DNS is typically bound to it, and cross-platform support only adds to the challenge. While building NetBird's DNS feature to access internal resources and private K8s clusters anywhere without exposing them publicly, we ran into this issue. Our solution combined Go, eBPF, and some XDP “magic” to let multiple DNS resolvers share the default DNS port 53 and enable secure access to private K8s clusters through a peer-to-peer WireGuard network. In this talk, we’ll walk through the story of how the NetBird team cracked the challenge using smart DNS handling on Linux and practical eBPF/XDP usage examples.