Strange ICMP-Request from ASG itself

Hey Guys

I have a strange behaviour of an ASG220 with 8.304.
The following entry shows up every 5-10 seconds in the packet filter log:

18:02:37 Default DROP ICMP 192.168.40.1 → 192.168.40.27 len=76 ttl=64 tos=0x00 srcmac=0:1a:8c:16:e9:90

192.168.40.1 is the internal IP of the Astaro, the other one is randomly chosen, once its the mailserver, then its a dc, then some irrelevant infra-server...

The sourcemac corresponds to eth0 of the Astaro (internal).

Any ideas what this could be?

Thank u and kind regards