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listen sets the UDP port Nebula will use for sending/receiving traffic and for handshakes.

port: 4242
batch: 64
read_buffer: 10485760
write_buffer: 10485760


host is the ip of the interface to use when binding the listener. The default is, which is what most people should use.


port is the UDP port nebula should use on a host. For a lighthouse node, the port should be defined, conventionally to 4242, however using port 0 or leaving port unset will dynamically assign a port and is recommended for roaming nodes. Using 0 on lighthouses and relay hosts will likely lead to connectivity issues.


Default: 64

Sets the max number of packets to pull from the kernel for each syscall (under systems that support recvmmsg).

read_buffer, write_buffer

Configure socket buffers for the udp side (outside), leave unset to use the system defaults. Values will be doubled by the kernel. Default is net.core.rmem_default and net.core.wmem_default (/proc/sys/net/core/rmem_default and /proc/sys/net/core/rmem_default). Maximum is limited by memory in the system, SO_RCVBUFFORCE and SO_SNDBUFFORCE is used to avoid having to raise the system wide max, net.core.rmem_max and net.core.wmem_max