dynamic proxy (--proxy dynamic,type=goagent,dns_record=goagent1.fqrouter.com), change the proxy via dns
detect the traffic protocol (HTTP/HTTPS), not just based on port
for http, the first request/response will be tried with proxy, if anything goes wrong fallback to another proxy. so, it is effective against GFW full text filtering. the page http://zh.wikipedia.org/zh/防火长城 is a typical example of full text filtering (the url does not trigger to RST)
for https, socket connect and full ssl handshake will be tried, if anything goes wrong (https certificate filtering for example), fallback to another proxy.
built-in support goagent as proxy, without starting an seperate goagent process