[Slackbuilds-users] ftp server not accessible

[Noel Butler]

On 22/02/2025 18:32, B. Watson wrote:

> Actually... if I understand how NAT64 and DNS64 work, he should be
> able to connect to the IPv4 address if there's no AAAA record at all.

Not so sure about ftp, I confess its been 20 years since I've even 
skimmed over anything nat64 so I'd be honest and say I'm working off an 
aged memory :) we never had a need for it, but I'm sure I recall there 
was a problem with certain protocols and ftp was one? They may have come 
up with a solution to that by now, maybe they have and that's why Marco 
is trying to use it.

> See https://en.wikipedia.org/wiki/IPv6_transition_mechanism#DNS64
> 
> DNS64 gives a 'synthetic' IPv6 address for a real IPv4 one, and NAT64
> allows an IPv6-only host to connect to it.

yes embedding 32b address inside it, and needs gateway set up correctly 
if any part of my memory is not muddying the waters.

> AFAICT, the problem is caused by us having an AAAA record, but not
> really listening on the IPv6 address.

Oh, didn't realise that part, I just thought there was a failure of 
routing, bit strange giving it a 6 DNS address but not using it, not 
sure what daemon is used, we've used pure-ftpd since about 2000-ish and 
it just uses every interface, , maybe its just a firewall that needs 
altering? But sounds like the daemon requires it implicitly be set?

> His machine doesn't think it needs to use DNS64/NAT64 because it
> sees there's a real AAAA record, so it tries to connect to the real
> IPv6 address, which gives 'connection refused'. If we got rid of the
> AAAA record entirely, DNS64 and NAT64 would be used instead.

Makes sense, but why not just make sure its accepted rather than remove 
the 6 DNS :)  Does Robby run it still? I'd like to ask him to change 
mailman too, but I'm thinking the version is not current enough to 
understand the changes, it's late Saturday night and you can guess what 
that means so I'll look in the morning hehe and if it meets requirements 
I'll shoot him off an email.

> 

-- 
Regards,
Noel Butler
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