Changing Default IP address & Configuring Management Port

Essentially this sounds like ARP FLUX. https://shradha741.medium.com/the-arp-flux-problem-3a4c92157f79

SFOS will respond to ARP requests for "every interface" within itself. So to speak: If you are connected to Port2 and send a ARP Request for 172.16.16.16, the Firewall will answer. 

We will essentially fix this in the future, if you do not want this. 

But usually a client is not requesting such IPs all the time. 

But isnt having the default ip configured could be considered a security breach? 

If a firewall is reachable via LAN (172.16.16.16) nothing will happen in this stage. It is just the reachable part. You should look into hardening your firewall:  Hardening Your Sophos Firewall 

But essentially it is not a security breach, if you firewall is reachable. It is the same level of reachable like you check your default gateway and then try to access the default gateway. 

alright thank you, I am just wondering also even if the port is not active and not plugged it still cause the ARP flux? Also, would it be ok to configure now the management port or also this will cause any disruption? Should I create a completely different zone for it and allow lan rule connection to it or should I include it in LAN zone? Sorry asking alot. Still new to the system and it is already preconfigured.

You can configure an Interface with another IP, it should not be the same Network Subnet, but any kind of other interface subnet is totally fine. 

thank you, but it should be added to the LAN zone right? 

Hi Reem Jalal Eddine , yes REF - How to configure management ports