Firewall message

RouterOS Beginner Basics
1

Hi,All!!
I have multiple messagess in my router log with same conntent.
Can someone explain it?

Time: Dec/22/2020 07:51:32
Buffer: memory
Topics: firewall
info
Message: dstnat: in:sfp1 out:(unknown 0), src-mac 00:23:3e:5e:7f:9a, proto TCP (SYN), 87.251.67.74:34330->my external ip:57816, len 52

Is that some kind of attack?
Thank You

2

Some of your firewall NAT rules has enabled logging, so you see this message when matching connection comes in. Find which one, check what if does, if you need it, etc.