Random network outage - restart of firewall

Question

I have been running the (XG) Firewall at my house for 4 years now and I have had this problem the whole time. 
 ISSUE: Randomly the internet stops working and within 10 seconds all the access points will also go offline where the red light comes on. After about 4-5 minutes everything comes back online. It seems like a service on the firewall basically just restarts. I have looked in all the logs available to me within the UI and nothing is obvious to me, no errors. 
 Can someone point me to other logs where I can look what could be happening? 
 My configuration follow: 
 
 Centurylink 100mbs fiber 
 Connects to Centurylink provided router/AP (I did not make much of an effort to connect the firewall directly to the Centurylink modem) 
 (3) APX 120 access points

Erick Jan · Answer

Hi Jerry, 
 Thank you for reaching out to Sophos Community. 
 To verify, are you running a Sophos Home or a Sophos firewall hardware(business user)? 
 Kindly check csc.log, applog.log, syslog.log, msync.log and networkd.log 
 Additionally, any coredump on the date of the failure under /var/cores 
 Check the firewall for Memory and CPU usage 
 Additional to check 
 
 Health checked/Hardware Resources 
 
 Top/Diagnostic

Network Interface
 
 Cables/NIC/switch and so on

Log files for modules 
 Sophos Firewall: Appliance crashes, restarts, or is non-responsive 
 XG 135 internet loss, every after 20 minutes

If you&rsquo;re a business user, I recommend creating a case, as this has been happening for 4 years.