# Opnsense - Firewall

DevFeed: [Opnsense - Firewall](<https://devfeed.tech/articles/opnsense-firewall-10756.md>)

Original publisher: [Read original article](<https://eduuh.com/blog/opnsense-firewall>)

Author: EduuhMuraya

Published: 2026-03-04T00:00:00Z

Content type: article

Language: en

Sources: [EduuhMuraya](<https://devfeed.tech/sources/eduuhmuraya.md>)

Topics: [Firewall](<https://devfeed.tech/topics/firewall.md>), [Internet of things](<https://devfeed.tech/topics/iot.md>), [networking](<https://devfeed.tech/topics/networking.md>), [configuration](<https://devfeed.tech/topics/configuration.md>)

Tags: [dns](<https://devfeed.tech/tags/dns.md>), [firewall](<https://devfeed.tech/tags/firewall.md>), [infrastructure](<https://devfeed.tech/tags/infrastructure.md>), [network](<https://devfeed.tech/tags/network.md>), [opnsense](<https://devfeed.tech/tags/opnsense.md>), [policy](<https://devfeed.tech/tags/policy.md>), [security](<https://devfeed.tech/tags/security.md>)

## AI overview

An examination of the live OPNsense firewall rules used to isolate an IoT segment, including default-deny behavior, rule ordering, DNS access, firewall-address boundaries, and device-to-device blocking.

## Source excerpt

The rules that seal my IoT segment, in the order they have to be written, and the two that look redundant until you understand what they are for.