OPNsense Forum

English Forums => Intrusion Detection and Prevention => Topic started by: Q3tNHn on December 10, 2024, 07:51:02 PM

Title: Can IPS only work for certain source subnet?
Post by: Q3tNHn on December 10, 2024, 07:51:02 PM
Hi all,
Can I setup IPS to make it only work for certain subnets behind a specific interface?
This is my setup diagram:
A L3 switch with vlan 10, 11, 12 connect to the LAN port on OPNsense. 
L3 switch IP address: 192.168.(10)(11)(12).1/24
LAN OPNsense address: 192.168.10.100/24
The L3 switch handles the east-west bound traffic, the OPNsense firewall handles the north-south bound traffic.
I want the IPS system on OPNsense only filter the north-south bound traffic(in and out) from 192.168.12.0/24 and 192.168.10.0/24 and ignore the 192.168.11.0/24 subnet.
Please tell me how to do that on OPNsense!
Thank you! 
Title: Re: Can IPS only work for certain source subnet?
Post by: meyergru on December 10, 2024, 08:09:20 PM
The subnets correspond to logical interfaces (= VLANs). See this:
Title: Re: Can IPS only work for certain source subnet?
Post by: Q3tNHn on December 10, 2024, 08:57:01 PM
Is there possible in the future to add the function?
Title: Re: Can IPS only work for certain source subnet?
Post by: meyergru on December 11, 2024, 12:06:04 PM
You obviously did not get my point (or I did not get yours): You can choose on what interfaces you enable IPS. Each interface corresponds to one of your subnets, so you can choose which subnets IPS acts upon.

So what are you missing that should be added?
Title: Re: Can IPS only work for certain source subnet?
Post by: Q3tNHn on December 11, 2024, 08:18:52 PM
Those subnets are not on the firewall Vlan.
Title: Re: Can IPS only work for certain source subnet?
Post by: meyergru on December 11, 2024, 08:51:42 PM
Well, at least they are behind SOME interface connected to OpnSense. You could add a bypass rules like this one:
Title: Re: Can IPS only work for certain source subnet?
Post by: Q3tNHn on December 14, 2024, 02:17:55 AM
Thank you!