The default gnutella port is 6346. However, you can usually also safely use ports between the range of 49152 - 65535. 64049 seems to work well for those who have their ISP blocking or shaping bandwidth on the 6346 port. For port forwarding, it's recommended you use the same port for both connecting & listening. However this is not mandatory. UDP & TCP can also be port forwarded separately which is recommended by some people.