A simple DNS forwarder that forwards DNS queries to various upstreams. If an upstream returns NXDomain, the next upstream is tried.
Usage of ./sparse_dns:
-debug
Debug mode
-listen string
Address to listen to (TCP and UDP) (default ":53")
-maxclients uint
Maximum number of simultaneous clients (default 1000)
-maxrtt float
Maximum mean RTT for upstream queries before marking a server as dead (default 0.25)
-upstream string
Comma-delimited list of upstream servers (default "8.8.8.8:53,8.8.4.4:53")