# require go1.11
go get github.com/mengzhuo/gontpd/cmd/gontpd

gontpd -c config.yml

# listen: gontpd service listen port (UDP)
listen: ':123'

# worker_num: goroutines per connection
worker_num: 1

# metric: prometheus stat listen port
metric: ':7370'

# peer_list: upstream peer list that sync to
up_state: 127.0.0.1:123
up_state_sec: 16

# acl: remote address within this list will be drop
# suggest to drop private net request(mostly are spoof request)
acl:
    - "192.168.0.0/16"
    - "172.16.0.0/12"
    - "10.0.0.0/8"
    - "100.64.0.0/10"

-A PREROUTING -p udp -m udp -t raw --dport 123 -j NOTRACK
-A OUTPUT -p udp -m udp -t raw --sport 123 -j NOTRACK

net.core.rmem_default = 5129920
net.core.rmem_max = 5129920
net.core.wmem_default = 5129920
net.core.wmem_max = 5129920

Intel(R) Core(TM) i7-4790 CPU @ 3.60GHz
~180kpps @ GOMAXPROCS=1