On Nov 13, 2008, at 8:55 AM, sqweek wrote:
I understand that if you import a gateway's /net on each computer in a rather large internal network you will be consuming a huge amount of mostly redundant resources on the gateway. My impression is that each imported instance of /net requires a persistent session to be established between the gateway and the host on the internal network. NAT in comparison is naturally
transient.

I'm not sure there's as much difference as you make out to be. On the
one hand, you have a NAT gateway listening for tcp/ip packets, and on
the other hand you have an open tcp/ip connection and a file server
waiting for 9p requests. It's not as though 9p is wasting bandwidth
chatting away while there's no activity, so the only cost is the
tcp/ip connection to each client on the network, which shouldn't
qualify as a huge amount of resources.

Exactly! An idle TCP connection costs you nothing except the state that
is kept by the kernels of the two connected end points. No packets
ever get generated unless there's an application level payload that
needs to be transferred. Not only that, but if you look at the amount
of state something like iptables on Linux needs to keep in order
to provide NAT capabilities it becomes a complete toss. With Plan9
as a gateway you're not paying a visible extra premium.

Thanks,
Roman.

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