port forwarding trouble

[Sergio Gelato]

* Frederik Eaton [2005-08-02 17:39:59 +0100]:
> Also, I don't think that the "host at port" syntax suggested in the bug
> comments is a good idea. 

At the very least it should be port at host. There is precedent for that,
e.g. in FlexLM LM_LICENSE_FILE environment variables.

>                          There should be some standard for ipv6, and
> we should use it. E.g., what do URLs use to specify the port when the
> host is specified as an IPv6 address?

I'm not sure about URLs, but various tools simply require square
brackets around the IPv6 address, as in
	[0:1:2:3:4:5:6:7]:port
For example, this (minus the port number) is what you are supposed to
do in /etc/hosts.allow. Implementations differ as to whether one needs
[fe80::]/10 or [fe80::/10] for network prefixes, but I think the former
is winning.

> A brief search indicated "host.:port" might be used somewhere. 
> But "host:port" is so common that it would be better to use a different
> notation only when 'host' is IPv6. "@" is especially bad, because it
> makes it look like the host is a user.

The [address]:port notation should be OK to use with both IPv4 (optional) 
and IPv6.