Re: avoid port forward over NAT

From: Bob (rbonham_at_rREMOVETHISaustin.rr.com)
Date: 12/10/03


Date: Wed, 10 Dec 2003 02:41:05 GMT

okay, I've got it now,

thanks for bearing with me...

that packet forwarding software you wrote sounds interesting...I am
wondering because I am working on a chat like program, and I am seeing that
I will be using a server too and polling it from the client, but probably
will not go to the lengths of making something that forwards any kind of
packet...

thanks again,

Bob

"CheshireCat" <blah@balh.com> wrote in message
news:aLrBb.496$rr3.3356@newsfep4-glfd.server.ntli.net...
>
> "Bob" <rbonham@rREMOVETHISaustin.rr.com> wrote in message
> news:90qBb.22533$HH.8506@fe1.texas.rr.com...
> > I understand that, but what I am not getting is this...
> >
> > BOTH computers are behind nat...
> >
> > NEITHER are using any port forwarding at all.
> >
> > but yet somehow A can make a connection to B.
> >
> > C is a computer running a "tracker" that has a description of the file
for
> > checking and keeps track of all the peers. It can't be behind nat unless
> the
> > ports are forwarded...but the data doesn't flow through C, it only
> supplies
> > a hash and a list of connections.
> >
> > the particular software that I have seen this work on is Bit Torrent.
> >
> >
> > even with C, I do not see how A can transfer data to B and vice versa.
> >
> > thanks for your patience.
> >
> > Bob
> >
> >
>
> AHHHHH I understand a bit more now!
> I visited the Bit Torrent site. It doesnt do anything special and suffers
> the same problems as other software behind a router/firewall. The FAQ says
> you need to set up your firewall if you need it to act as a server.
>
> FAQ quote -
> "I'm behind a firewall/NAT, can I use BitTorrent?
> Yes, but you will get better performance if other peers can connect to
you.
> By default, BitTorrent listens on port 6881, trying incrementially higher
> ports if it's unable to bind, and gives up after 6889 (the port range is
> configurable). It's up to you to figure out how to poke a hole in your
> firewall/NAT."
>
> I wrote a piece of proxy software a few months ago to overcome this
problem.
> It allows client and server to "connect" when one or other is behind a
> firewall. Both connect to a server running on a WAN server, where it will
> perform packet forwarding between the client and server machines.
> How do you know that A is directly connected to B?
> Even with peer file sharing software like Kazaa, there is a core set of
> servers that pass information around about other nodes. If you're running
> kazaa behind a firewall you need to enable port forwarding on the firewall
> if you want it to serve files. Kazaa or other p2p networks would die if
> every node was behind a closed router.
> Bittorrent mentions a HTTP server connected to the tracker software. The
> http software at least must have a pathway through the firewall.
>
> BTW, there are ways of broaching firewalls - socks proxy and uPnP
(probably
> others too) for applications that support them.
>
>



Relevant Pages

  • Re: More on Remote Desktop
    ... Chances are good, though, that he's already got VPN capabilities on his ... firewall to do it for $100. ... > server at home...or purchase additional/new hardware... ... >> my firewall makes the PPPoE connection to my ADSL ISP. ...
    (microsoft.public.windowsxp.network_web)
  • Re: More on Remote Desktop
    ... on your firewall to the world, you will almost certainly get hacked. ... between your clients and server on your own LAN. ... your laptop into that LAN server has got to be making these two public IP's ... PPPoE connection to my ADSL ISP. ...
    (microsoft.public.windowsxp.network_web)
  • Re: More on Remote Desktop
    ... Also note that if you use the default listening port for Remote Desktop there is no need to append ... >> point it to the Static IP of the internal server. ... >> firewall to get between your clients and server on your own LAN. ... >> mine setup so that my firewall makes the PPPoE connection to my ADSL ISP. ...
    (microsoft.public.windowsxp.network_web)
  • Re: SBS 2003 Firewall, joining domain, logons
    ... Windows firewall doesn't run on the SBS - if it's running then we'd have ... The main windows of the firewall has a message 'windows firewall is using ... Ethernet adapter Server Local Area Connection: ...
    (microsoft.public.windows.server.sbs)
  • Re: SMTP Connector Problem
    ... when I choose don't change Firewall. ... > Damian N. Leibaschoff, MS IST, MCSE ... >> Ethernet adapter Server Local Area Connection: ...
    (microsoft.public.windows.server.sbs)