NS300 Not Reachable from Sophos XG4500, but Can Call Outside

Hi everyone!

I’m facing a puzzling connectivity issue in my PABX setup. My NS300 cannot be pinged from my Sophos XG4500 when my SIP router is connected to the core switch. However, I can still make calls outside, which adds to the confusion.

Coreswitch(ARUBA 3810M) Vlan90

• 192.168.90.1/27 Vlan 90

• 172.16.1.1/27 Vlan 1

NS300
IP: 192.168.90.30/27
GW: 192.168.90.1

SIP ROUTER
IP: 192.168.90.1/27 Signaling: 192.168.90.30/27

The Sophos XG4500 cannot ping the NS300 while the SIP router is connected to my Coreswitch But I can successfully call outside.

I’ve attached a diagram of my network setup for context.

Any insights or troubleshooting steps would be greatly appreciated. Thanks for your help!