It's difficult to determine if there's a content filter like a p2p sharing filter. An example of one of these is Sandvine which is becoming popular at some isp's: http://www.sandvine.com/products/p2p_element.asp

Some isp's block ports or specific p2p share programs or all known gnutella programs. So which option they've gone for can be determined by trying different ports, different gnutella clients & different p2p sharing programs. Oh & isp's if they are using a filter, they may be applying it universally or just against particular users they've detected using p2p or the program itself detects p2p use. One option in answer to this is to use a proxy of some type. You'll find a link to setting up proxies in the sticky threads in this section.

How to change the port for LW: Go to Tools>Options>Advanced>Firewalls & change the listening port from 6346 to another. I'd recommend trying feach of these port no.'s: 3500, 1203, 80, 20282, & 443. After changing the port no., press the apply button. Then go to the menu File>Disconnect & wait a minute. Then go File>Connect & give it 20 or more mins to allow it to connect. Try this for each suggested port no. if the 1st ones don't work.

If you run 2 limewires on 2 computers connected to a router that doesn't utilise UPnP then you'd need to forward a separate port for each one.

Also remember that some modems/routers don't utilise UPnP so you may need to do port forwarding(opening a port.) THis is b/c these devices use NAT firewalls which block out all ports except that for browsing. If you need to do port forwarding then please supply your connection devices brand & model no.'s

There's a way to check other ports being open but you must have LW open at that time before you do the test. http://jlh.no-ip.org/connectiontest/ And change the port no. you wish to test.