Hello Alex,

 Syslog-ng can be compiled with or without IPv6 support. As a first step please verify if it was compiled that way.

 If you start Syslog-ng with the "--version" option it will print a little debug information about itself. Among other options there will be a line: "Enable-IPv6"

 (If it was compiled with "Enable-IPv6: on", please copy the entire output here. It will help with the later investigation.)

Best regards,

Laci

---

From: syslog-ng <syslog-ng-bounces@lists.balabit.hu> on behalf of Alexandre Santos <alexandre.rosas.santos@gmail.com>
Sent: Friday, August 28, 2020 12:35
To: Syslog-ng users' and developers' mailing list <syslog-ng@lists.balabit.hu>
Subject: [syslog-ng] No remote logging with hostname which has address is IPv6

 

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Hi,

I have configuration, which is sending log messages to a remote hostname (dns6server). The particularity of this remote server is that it is resolved to an IPv6 address.

ping works fine:

root@localhost:~# ping dns6server -c 3
PING dns6server(2620:38:4::8:4000:238) 56 data bytes
64 bytes from 2620:38:4::8:4000:238: icmp_seq=1 ttl=63 time=0.354 ms
64 bytes from 2620:38:4::8:4000:238: icmp_seq=2 ttl=63 time=0.264 ms
64 bytes from 2620:38:4::8:4000:238: icmp_seq=3 ttl=63 time=0.310 ms

But syslog-ng seems not to be able to resolve the ipv6 address:

Aug 27 20:58:37 localhost systemd[1]: mgmt-syslog-ng.service: Succeeded.

Aug 27 20:58:37 localhost systemd[1]: Stopped External Logger Daemon.

Aug 27 20:58:37 localhost systemd[1]: Starting External Logger Daemon...

Aug 27 20:58:37 localhost ip[32709]: [2020-08-27T20:58:37.841389] WARNING: With use-dns(no), dns-cache() will be forced to 'no' too!;

Aug 27 20:58:46 localhost ip[32709]: [2020-08-27T20:58:46.854714] Error resolving hostname; host='dns6server'

Aug 27 20:58:46 localhost ip[32709]: [2020-08-27T20:58:46.854758] Initiating connection failed, reconnecting; time_reopen='60'

Aug 27 20:58:46 localhost systemd[1]: Started External Logger Daemon.

Any Ideas?

I am sending the configuration and debug log in attachment.

Thanks in Advance,

Alex

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