Q: Odd connection on network

I was running through my firewall (commodo free firewall) logs on my computer at work and noticed a weird regular connection. We have 10 or so individual computers all connecting into a main server (it handles emails, emails out to a couple of mobiles, internet & our work files and not that much else).

My firewall shows that one of the other machines on our network connects to 255.255.255.255 at port 23497 every 5 seconds, each time from port n+1 (just increases by 1 every 5 seconds). I might be wrong but im guessing my firewall will only block - or see connections made to myself? - or is it likely that this is some network wide broadcast that only specific computers respond to perhaps?

My only thoughts are either his mobile is setup to check the emails on the server rather too regularly, there is some network monitor on his machine or there is some port scanning type virus/ problem on the machine.

Any ideas what this might be? or what i can dig about to see. The computer this originates from is my boss' so i don't want to bother him about it unless its something serious.

TY for any help.

 

It's a subnet broadcast on the network and absolutely harmless.