Drilldown on egress alerts

  • Hi all, hope this is the correct place to ask a question about identifying source of egress alert. After enabling snort ETs I'm occasionally getting ET MALWARE alerts with my WAN as source IP.
    Given I have several hosts, including wifi based that have a pfsense issued local IP but are coming in from one interface; what is the most effective way to identify the source of the bad traffic?
    Do I need to enable Suricata on all interfaces? or is there a more detailed long entry for each alert that includes the local LAN source? (All my interfaces are members of one LAN Bridge)

    Thank you so much.

  • The best place to run an IDS/IPS such as Snort or Suricata for home networks is on the LAN interface.  That way host IP addresses in alerts will be shown with their native addresses.  When you run the IDS on the WAN, all alerts will have the WAN IP as the "local host" address since the IDS sees traffic outbound on the WAN only after NAT rules have been applied.

    There are number of posts in this sub-forum by me and others that talk about this.  So move your configuration over to the LAN interface and your problem will be solved.  Internal hosts will show up in the alerts with their own IP address.


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