Passive-to-Passive

[Mek 13]

Hey,

just curious about the passive-to-passive user connection. How does that work?

I tried it in our university campus where we have no NAT (we get public IPs) but our IP addresses are firewalled by a keep-state firewall so passive mode is the only option. In this case, connection to passive users in passive mode didn't work - I suppose it has to do something with the "NAT Traversal". Would it be possible to support passive-to-passive connections even when no NAT is in effect?

[Big Muscle 1]

what DC protocol do you use? ADC or NMDC?

[Mek 13]

NMDC

[Big Muscle 1]

You must use ADC to get it fully work. It shouldn't depend whether NAT, firewall or nothing is used and should work in almost all cases. It works in NMDC only under certain conditions, because many NMDC hubs violates this old protocol.

[Lotus 0]

Yes, but can you be more specific ? How exactly does it work ?

It is a very interesting and powerfull option. Today almost 2/3 of users are passive.

I think this feature deserve more credit and some explanations so hub owners can understand it.

Thank you.

[Big Muscle 1]

check this: http://dcpp.wordpress.com/2010/02/13/passive-mode-c-c-connections-and-nat-traversal/

briefly: if there's connection between A-S and B-S (S is hub in our case), you can bind ports to create connection between A-B.

[Lotus 0]

Thank you. Very useful informations.

[PPK 0]

Would it be possible to support passive-to-passive connections even when no NAT is in effect?

That is possible.. but then it will be another skype, using active users for passive->passive data transfers (and i'm sure that is something that nobody want to do).