Port numbers must only be unique for ip:port pairs. A TCP connection is identified by the "quadruple" source_ip:source_port, dest_ip:dest_port. You can have as many connections as you want on the same source_ip on port 80 as long as there aren't 65,535 to the same dest_ip (ie as long as the quadruple is unique).
Cheers for the info! I guess that's where I got the wrong idea from - attempting to stress test one machine from another machine, I'd always hit that limit, but now I understand why.
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At the risk of sounding dumb, aren't we still limited to 65,534 ports on an interface?
Port numbers must only be unique for ip:port pairs. A TCP connection is identified by the "quadruple" source_ip:source_port, dest_ip:dest_port. You can have as many connections as you want on the same source_ip on port 80 as long as there aren't 65,535 to the same dest_ip (ie as long as the quadruple is unique).
Cheers for the info! I guess that's where I got the wrong idea from - attempting to stress test one machine from another machine, I'd always hit that limit, but now I understand why.
Try Tsung for stress testing, it can use multiple IPs and therefore you can open up as many connections as you like -
http://tsung.erlang-projects.org/
Also with IPv6 you can easily route a whole /64 net (264 IPs!) onto a single machine.
2^64 IPs. :)