prosodyctl check and xmpp behind nat

[Autopot France]

Hello,

I have this message

# prosodyctl check
Checking config...
Done.
   Failed to determine the external addresses of this server. Checks may be inaccurate.
Checking DNS for host mydomain.org...
    serv.mydomain.org. A record points to unknown address 1.1.1.1
    Host serv.mydomain.org. does not seem to resolve to this server (IPv4/IPv6)
    No targets for mydomain.org appear to resolve to this server.

My xmpp server has a private IP address and is natted but serv.mydomain.org point to the public IP address 1.1.1.1
I think the xmpp server is complaining because it tries to resolve the DNS record but doesn't find it locally.

Does anyone know how to deal with prosody being natted ?
Is this error important ?

Regards

[Kim Alvefur]

Hi,

On Thu, Aug 09, 2018 at 03:11:48PM -0700, Autopot France wrote:
> I have this message
>
> # prosodyctl check
> Checking config...
> Done.
> Failed to determine the external addresses of this server. Checks may be
> inaccurate.

Note how it says "Checks may be inaccurate".

> Checking DNS for host mydomain.org...
> serv.mydomain.org. A record points to unknown address 1.1.1.1
> Host serv.mydomain.org. does not seem to resolve to this server
> (IPv4/IPv6)
> No targets for mydomain.org appear to resolve to this server.
>

> I think the xmpp server is complaining because it tries to resolve the DNS
> record but doesn't find it locally.
>
> Does anyone know how to deal with prosody being natted ?

Are you experiencing problems with Prosody itself? Generally, being behind
NAT should not be an issue as long as ports are forwarded correctly.
This is however tricky to determine from inside the NAT.

> My xmpp server has a private IP address and is natted but serv.mydomain.org
> point to the public IP address 1.1.1.1

Then just make sure the relevant ports are forwarded from the firewall
and it should work.

> Is this error important ?

There's an issue reported here: <https://issues.prosody.im/964>

It is unfortunate that it is mistaken for an error. Suggestions for
better wording are welcome.

`prosodcytl check` is a tool to check for common problems, but it is not
perfect. In this (NAT) situation, it is unable to check if your DNS is
configured correctly because it does not know the public IP address.

If Prosody itself is working for you and your clients then don't worry
about the check.


--
Regards,
Kim "Zash" Alvefur

[Autopot France]

Thank you Kim for your answer.

I think (like other softwares), there should be an option on the configuration file saying
# In case Prosody behind NAT
public_ip = 1.1.1.1
So that prosody could correlate what it sees as its IP address and what it finds in the DNS answer.

Regards

[Matthew Wild]

On 10 August 2018 at 23:21, Autopot France <autopot...@gmail.com> wrote:
> Thank you Kim for your answer.
>
> I think (like other softwares), there should be an option on the
> configuration file saying
> # In case Prosody behind NAT
> public_ip = 1.1.1.1
> So that prosody could correlate what it sees as its IP address and what it
> finds in the DNS answer.

I have thought about this, but it's not very useful for people with dynamic IPs.

I've been thinking of adding a --nat parameter to prosodyctl check
instead, possibly with a way to pass the external IP. There are still
setups that this would not cover, however.

Regards,
Matthew

[za...@zash.se]

Lördag den 11 augusti 2018 skrev Matthew Wild:
> I've been thinking of adding a --nat parameter to prosodyctl check
> instead, possibly with a way to pass the external IP. There are still
> setups that this would not cover, however.

Maybe it's enough to check for private IP ranges and print "If your public IP is what's in DNA and your firewall, port forwarding is in order then you're good."

--
Zash