No it doesn't have to be. Port 6346 is simply the official gnutella port but you can use any of the legal port no.'s. A Guide To Alternative Port Selection

I'm not sure why anybody's port no. within LW should change from one occasion to the next.

I've heard of other people having issues in apartments where there's shared connections. And as Grandpa said, there's probably a NAT firewall within the main router. I guess you could ask the landlord if they could open port 6346. I wonder also if, with everybody sharing the one connection, whether the connection gets a bit strained at times. There's so many possibilities. Such as an unreliable router losing packets. Also, the isp provider might also be filtering/shaping against p2p sharing. It would be helpful if you could find out who the isp (internet service provider) is.

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