Issue Can't use IPv6 address for backups

[Webbenny]

Hello!

I've tried to use a IPv6 address as an FTP Backup location. But it seems that Plesk can not handle IPv6 addresses nor resolve domain names with only a aaaa-record (and no a-record).
I there any workaround for this issue? Is it planed to fix this in future, because Plesk already supports IPv6 as web/mail/ftp server?

Regards Benny

 

[UFHH01]

Hi Webbenny,

for further investigations, you could consider to post the corresponding log : /usr/local/psa/PMM/logs/pmmcli.log

 

[Webbenny]

Thanks for your reply. I've tailed (tail -f) the pmmcli.log. And nothing was logged, if I changed the Hostname. It seems that the file is only written if I leave the screen but I can't leave because of the following errors:
In case I entered the IPv6 address I got: Server name is invalid.
In case I enetered the FQDN (which has only an AAAA record): Using the local Plesk's FTP server as a remote storage is prohibited. Please specify a remote location.
So I conclude that Plesk doesn't sopport ivp6 backup locations. This is very sad, because more and more infrastructures are running with ipv6...
Is that IPv6 support on your roadmap?

 

[UFHH01]

Hi Webbenny,

If you desire further investigations, you should consider to post the IPv6 ( or the corresponding FQDN of the IPv6 ) and as well the Plesk-Server-IP, from which you would like to backup from.

 

[Webbenny]

So I wont post my productive space, I've setup a test scenario.
My FTP-Server IP is: [2a02:8071:4100::5164:7a8d:33cb:c67] or ipv6.38i.de

From the bash of my Plesk-Server this works (with lftp, same with filezilla):

lftp :~> open ftp://ftpuser:[email protected]
lftp [email protected]:~> set ssl:verify-certificate false
lftp [email protected]:/> get php7ts.dll
8638464 bytes transferred in 54 seconds (156.2K/s)
lftp [email protected]:/>

You could use the credentials:

User: ftpuser
Password: OQJBrtA8PgVbNnijZ4z2

User is read-only.

 

[UFHH01]

Hi Webbenny,

DNS Traversal
Action Host Zone
Starting at a.root-servers.net. [2001:503:ba3e::2:30] .
Referred to sec1.apnic.net. [2001:dc0:2001:a:4608::59] ip6.arpa
Referred to ns3.afrinic.net. [2001:500:14:6100:ad::1] 0.a.2.ip6.arpa
Referred to dns02.kabelbw.de. [2a02:8070:0:201:82:212:62:58] 1.7.0.8.2.0.a.2.ip6.arpa


DNS Results
dns02.kabelbw.de. [2a02:8070:0:201:82:212:62:58] says:


Name Type TTL Value
No name server returned any records for this request.

=> DNS Lookup for 2a02

There is no rDNS - entry for "2a02:8071:4100::5164:7a8d:33cb:c67", which makes it impossible to use the IPv6 over the Plesk Control Panel as remote backup repository.

... and using "ipv6.38i.de" as IPv4, results in:

Searching for ipv6.38i.de. A record at C.ROOT-SERVERS.NET. [192.33.4.12] ...took 1 ms
Searching for ipv6.38i.de. A record at z.nic.de. [194.246.96.1] ...took 1 ms
Searching for ipv6.38i.de. A record at ns1.antagus.de. [195.191.92.10] ...took 9 ms

Nameserver ns1.antagus.de. reports: No such host ipv6.38i.de

 

[Webbenny]

Hi UFHH01,

I'm wondering for which purpose a rdns should be required (you don't need to have this for IPv4 addresses, too)? This is just a usual FTP connection..
Yes, ipv6.38i.de has no A-Record, only a AAAA-Record which is usual (look at ipv6.google.com) for ipv6 only domains.
Is there any offical statement that plesk (not) supports ipv6 FTP-Backups?

Best regards, webbenny

 

[UFHH01]

Hi Webbenny,

the desired IPv6 - address doesn't resolve anywhere, as you can see. While your FQDN "38i.de" resolves to "92.51.146.68" ( which is a server IP from Hetzner ). As you noticed, there is no reverse entry "ipv6.38i.de", which possibly points to your IPv6 "2a02:8071:4100::5164:7a8d:33cb:c67" , which forces Plesk to resolve to your server IP => Result: Plesk can't resolve the IPv6 and uses the FQDN instead, which points to its own server IP and you see: Using the local Plesk's FTP server as a remote storage is prohibited. Please specify a remote location.

A test file couldn't be uploaded as well to your IPv6 - system: => FTP-Server-Verbindungstest

 

[Webbenny]

Hi UFHH01,

the desired IPv6 - address doesn't resolve anywhere, as you can see.

Thats the point. Why should my IPv6 address resolve anywhere? Why should a direct IP--IP connection without any DNS lookups not be possible for Plesk?

While your FQDN "38i.de" resolves to "92.51.146.68" ( which is a server IP from Hetzner ).

This should not be a problem, this entry is only valid for the upper level domain (38i.de) I used the subdomain ipv6.38i.de. If Plesk lookups up the the next higher domain level, this is a bad technical practice an indicator that it doesn't support IPv6 on Backup locations...

As you noticed, there is no reverse entry "ipv6.38i.de", which possibly points to your IPv6 "2a02:8071:4100::5164:7a8d:33cb:c67" ,

Why is such a record required? rDNS records are required for mailing check scenarios, but not for "client like" connection from plesk to a FTP Server. All I need here is a AAAA-Record with a IPv6 IP.
Plesk musst resolve forward (name -> IP).

A test file couldn't be uploaded as well to your IPv6 - system: => FTP-Server-Verbindungstest

Yes it's temporary read only, I have changed this. But this has no impact on the Plesk connection problems.

The technical question is, why is it a problem for Plesk, if all other clients can handle this? If there is really any trouble with DNS other connections can not work, too...
I assume that the field value check or other checks blocks my IPv6 entry...?!

 

[Webbenny]

Short information: Same scenario with IPv4 works without problems (no rdns set etc.). Is anybody from the plesk team able to give a comment to the ipv6 backup topic?

 

[IgorG]

Is anybody from the plesk team able to give a comment to the ipv6 backup topic?

We have the corresponding bugreport PPP-17519 about impossibility to use IPv6 address for ftp backup repository. Fix is planned for one of nearest Plesk major updates.

 

[Webbenny]

Wow. Great news. Thank you!

 

[mcac]

Hi, I have also problems to connect to an IPv6-Backup-Storage. I tried to insert the IPv6, [IPv6] and a hostname which pointed to the IPv6 (AAAA-Record, but without A-Record). What can I do? Is PPP-17519 fixed?

 

[o.m.]

Hello, any news on this issue? A have a similar problem: a domain with a subdomain with only an aaaa-record. I set up backups to this subdomain and the reaction to this is on one server
"Using the local Plesk's FTP server as a remote storage is prohibited. Please specify a remote location".
On another server the same domain name gets accepted but the backup fails with
"Unable to create the remote backup: Transport error: unable to check directory existence: Curl error: (19) FTP: couldn't retrieve (RETR failed) the specified file: Last FTP request: NLST Last FTP response: 550 No files found".
An interesting fact: if the given directory doesn't exist on my backup server, the remote storage setup on the second server doesn't accept the settings accordingly - so the setup can read the server but the backup process seemingly wants to rely on ipv4 which isn't there.
In less than 2 months we can celebrate the 5-year-anniversary of this issue, yay!