brain-dump/networking

Linux-based Router Firmware

Notes for DD-WRT and OpenWRT router firmware.

DD-WRT

• Troubleshooting - Initial install failures
• Hosts - Network-based ad and malware filtering, without additional hardware
• Wifi VLAN setup - Guest wifi network setup

OpenWRT

• Wired switchport VLAN - Isolate untrusted wired devices
• Wifi VLAN - Isolate untrusted wifi devices / guest network
• SSL Setup - Enabling SSL connections on the Luci gui
• Freeing Space Freeing up storage space

Post Installation

• Custom DNS - DNSCrypt setup/upgrade warning
• Additional Security - Even with previous hardening, some stuff slips through the cracks
• Troubleshooting - OpenWRT troubleshooting
• Site Blocking - Ad and tracker filtering on OpenWRT

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Most of these instructions were written for OpenWRT 17.01.6; for 18.06+, they are largely still valid - with the exception of iptables -state (which is deprecated in later versions.)

OpenWRT Fix

If you try to use the obsolete shared library, you'll see:

iptables v1.6.1: Couldn’t load match `state’:No such file or directory

Instead of (works in 17.01.6 - breaks in 18.06):

iptables -I FORWARD 1 -m state --state RELATED,ESTABLISHED -j ACCEPT

Use this, instead:

iptables -I FORWARD 1 -m conntrack --ctstate RELATED,ESTABLISHED -j ACCEPT

conntrack has superseded state

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DD-WRT latest utilized Oct 19, 2018 beta; r37442 (never had a single issue with DD-WRT throughout all of my upgrades, always stable and awesome despite being labled a beta release) -- the primary issue I take with DD-WRT is limited support for VLAN switchports.

Only Broadcom based devices support port-based VLAN's, no Atheros or Ralink devices.

While DD-WRT limits VLAN port capability, OpenWRT fully supports Atheros; based on the routers I've configured.