[Solved] Synology nas log collection via tailscale

SUPPORT QUESTIONS
1

Tailscale version : 1.20.0 & 1.22.2
Your operating system & version : Synology DSM 6.2.4

I have a RPi running tailscale 1.22.2 and a synology NAS running tailscale 1.20.0 .

The two devices can see and use each other (using tailscale IPv4 and IPv6):

  • I can ping the nas from the RPi
  • I can ssh login to the NAS from the RPi
  • I can mount the NAS from the RPi

I’ve configured the RPi to send its logs to the NAS, however, I can’t get the log of the RPi to be displayed in Synology Log Center. When runing tcpdump on the NAS, I can see the logs from the RPi arriving to it on the tailscale interface.

Does anybody have an idea of what could be wrong ?

2

The RPi has been configured to send Syslog (UDP port 514) to the Synology?

I guess it is possible that the Synology Syslog receiver is hard-coded to listen on its LAN port. I don’t see a setting for interface in the documentation, which usually means it will listen on all interfaces not specifically LAN.

3

Yes it has been configured to send the log to the NAS, as I can see these messages when doing a tcpdump on the correct port (514) on the NAS.

As far as I can tell, the syslog service does listen on all interfaces. As show by the command below (run on the NAS)

# netstat -lupn | grep syslog
udp        0      0 0.0.0.0:514             0.0.0.0:*                           32442/syslog-ng     
udp6       0      0 :::514                  :::*                                32442/syslog-ng
4

In fact, it’s working correctly, the Synology Log Center does receive the logs from the distant RPi via tailscale.
It turns out this RPi is in another timezone, so the logs are arriving with a time that is in the past. So my issue is with the rsyslog config, nothing to do with tailscale.