获取国内路由表

@bellchu 这样处理是精确点，但是路由表太长了，据说客户端接收不全?
curl ‘http://ftp.apnic.net/apnic/stats/apnic/delegated-apnic-latest‘ | grep ipv4 | grep CN | awk -F\| ‘{ printf(“%s/%d\n”, $4, 32-log($5)/log(2)) }’ > chnroute.txt