It’s 65k per end, but we’re generally expecting all traffic to come in on one port for one service.
To further complicate the issue, any proxies or NAT in between may reduce the number of “clients” seen. A naughty ISP may only allow you to talk to 65 k sessions at once, or per data center.
And then there’s load balancers, which increase the number of ports in use if you only have one IP.
To further complicate the issue, any proxies or NAT in between may reduce the number of “clients” seen. A naughty ISP may only allow you to talk to 65 k sessions at once, or per data center.
And then there’s load balancers, which increase the number of ports in use if you only have one IP.