Firewall live log sometimes shows random wrong source IP address

I've noticed a behavior this week that I have seen once and then when the live log suddenly starts showing wrong source IP addresses in the firewall log.

I think this was a bigger issue years ago but I thought this would eventually be fixed already.

Of course I cannot recreate it and searching for this is not as easy.

SFOS is 21.0

In this example I was searching for the username (heartbeat auth).

The user was working outside the office via SSL VPN. In the midlde of the logs I found wrong source IP from a LAN network. The LAN is a VLAN on the XGS lag0 and is only available in the building where the user wasn't physically. Also the user was not logged on a computer with that source IP. In fact the user never works physically on this company site.

Destination IP was to one of our DMZ IP routed by another firewall.



Edited TAGs
[edited by: Erick Jan at 12:47 AM (GMT -7) on 31 Mar 2025]