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Comment by cm2187 | Hacker News Reader

What's the point of using non standard ports with IPv6? If a machine can have a million different IPv6, why would one even bother using a non standard port?

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Because we have decades worth of existing software and existing standards which count on there being ports. We have standard ports for different software applications, we have changing port number on the same machine to reach a different service -- if we eliminated ports it wouldn't just replace IP addresses of one type with a new type, it would ALSO change lots of other things from the networking layer all the way up to the application layer.

I am not suggesting eliminating ports. The author describes having to specify a non standard port in the browser as a major annoyance. In a world where you have infinite IPs you would rather use another IP than listen to https on a non standard port.

Except we are heading in that direction anyway with software containers and efforts to give full networking support to them.

This is not a bad thing either - when all apps act like they're distributed, or could be, we'll get a lot better tooling for actually writing them.

Kind of like switching an addressing format?

One common reason is that binding to small ports requires root. If you are using a nonstandard port you would typically front that with a load balancer on the standard port. But if you are trying to debug the server itself, you might need to type in [abcd::1234]:8443 or something. This is not a concern for end users, but could be for sysadmins.

On Linux, you can use capabilities to avoid running as root. In the case of binding to ports lower than 1024, this would be by enabling the CAP_NET_BIND_SERVICE capability.

You can have millions if you manually configure them, the DHCPv6 and SLAAC will not grab several addresses for use.

That's no different from manually configuring non standard ports.

No, it's really not. You can ask the OS to allocate a new port when you start up a piece of software and then advertise that port via whatever coordination protocol you have.

If you're grabbing an IP address you have to, at least in theory, coordinate with other machines on the network to make sure it's not already taken. It's not the same.

> You can ask the OS to allocate a new port when you start up a piece of software and then advertise that port via whatever coordination protocol you have.

As long as the coordination protocol is not output a wrongly formatted url to the terminal and have the user cut and paste it into their browser, the coordination protocol should be able to handle it.

God knows what the standard will be when we start using IPv6, but I guess a datacentre would allocate each server a prefix of a few thousand ips. The server is then free to use any of them without any risk of collision. The point of this vast address space is precisely to enable the infrastructure to be a lot more stateless (as in not worrying about individual IPs).

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