Did you know that you can do more with your router? It is possible to have very granular control over everything that this all-important machine does. You just must unlock it.
I installed DD-WRT onto my Linksys WRT1900ACS router.
What is DD-WRT? “DD-WRT is Linux-based firmware for wireless routers and access points.” https://en.wikipedia.org/wiki/DD-WRT It is the software that enables your router work, just open-sourced, meaning it can be much more powerful and flexible than what comes prepackaged on your store-bought router. The tradeoff is that it is more convoluted to setup and it is much easier to break.
Steps to Follow:
- Download the required software for my Linksys WRT1900ACS
- Flash the DD-WRT image to my router
- Setup DD-WRT
- Setup Pi-Hole to serve as DNS server
1. Download the required software:
I went out to the DD-WRT website, and searched for my router. I own a Linksys WRT1900ACS Version 2. This ultimately led me to https://dd-wrt.com/support/router-database/?model=WRT1900ACS_v2. I also needed to download an older version of the Linksys firmware to install DD-WRT. It took some searching, but eventually I found what I was looking for here: https://www.userdrivers.com/LAN-Network-Adapter/Linksys-WRT1900AC-Router-Firmware-Update-1-1-8-161917/download/. This was required due to changes in Linksys more recent firmware. I could not just upload the new software. Fortunately, Linksys makes this easy. After the router rebooted, the firmware update was complete.
2. Flash the DD-WRT image to my router:
The first part of this is downgrading the current firmware on my router. Using the 1.1.8 version I obtained from userdrivers.com, I logged into my router at 192.168.1.1 and navigated to the “Connectivity” Tab. From there I selected “Firmware Update” and selected the appropriate file. Then I clicked “Start” followed by “Yes” and let the program run.
Now, I could load DD-WRT. I followed the exact same steps as above, but instead selected the DD-WRT Firmware instead of the Linksys. This time after the router rebooted, I had DD-WRT running!
3. Setup DD-WRT:
This is the long and tedious part. Many aspects of a router are automatically configured in most commercial models. I need to define everything. So, here’s a brief rundown of the basic setup I did.
- Router Name: Router Name
- Domain Name: URL pointed at my IP address
- DHCP Type: DHCP Server
- DHCP Server: Enable
- Start IP Address: 192.168.1.XXX
- Static DNS 1: 126.96.36.199
- Static DNS 2: 188.8.131.52
- NTP Client: Enable
- Time Zone: US/Central
Then I clicked “Save” and then “Apply Changes”
Since this is a dual-band router, it has two frequencies it broadcasts on, 2.4 GHz and 5 GHz. Each needs to be set up separately. The settings are the same for both channels except as noted.
- Wireless Mode: AP
- Wireless Network Mode: AC-Only (5GHz) and Mixed (2.4GHz)
- Wireless Network Name (SSID): The Banana Stand 5GHz (5GHz) and The Banana Stand (2.4GHz)
Then I clicked “Save” and then “Apply Changes” and I switched to the “Wireless Security” tab nested under the “Wireless” Tab
- Security Mode: WPA
- Network Authentication: WPA2 Personal
- WPA Algorithms: CCMP-128 (AES)
- WPA Shared Key: WiFi Password
Then I clicked “Save” and then “Apply Changes”
Now the router is ready for business as usual!
4. Setup Pi-Hole to serve as DNS server:
Using the Linksys Smartwifi software that came default on my router, all I had to do is enter the IP address of my Pi-Hole as a Static DNS server. And I was good to go. No longer. DD-WRT is a bit for tricky, but I did get it going.
- Open the “Services Tab”
- Select the next tab named “Services”\
- Scroll down to the DNSmasq settings
- Enable and Disable as seen in the image
- Under “Additional Dnsmasq Options” type: dhcp-option=6,192.168.1.101
- Scroll to the bottom of the page and hit apply settings, your pihole is now the DNS server for your router!
An additional setting can ensure that even devices with a DNS address hardcoded (I’m looking at you android phones and Chromecasts…) use the pihole.
Go to the Administration Tab > Commands and enter the commands and Firewall rules in the left image. Hit “Run Commands” and “Save Startup” when done.
Commands: iptables -t nat -I PREROUTING -i br0 -p tcp --ddport 53 -j DNAT --to 192.168.1.101:53 iptables -t nat -I PREROUTING -i br0 -p udp --ddport 53 -j DNAT --to 192.168.1.101:53 iptables -t nat -I PREROUTING -i br0 -p tcp -s 192.168.1.101:53 --dport 53 -j ACCEPT iptables -t nat -I PREROUTING -i br0 -p udp -s 192.168.1.101:53 --dport 53 -j ACCEPT Firewall: #keep network on pi-hole iptables -t nat -I PREROUTING -i br0 -p tcp --ddport 53 -j DNAT --to 192.168.1.101:53 iptables -t nat -I PREROUTING -i br0 -p udp --ddport 53 -j DNAT --to 192.168.1.101:53 #punch DNS hole for pi-hole iptables -t nat -I PREROUTING -i br0 -p tcp -s 192.168.1.101:53 --dport 53 -j ACCEPT iptables -t nat -I PREROUTING -i br0 -p udp -s 192.168.1.101:53 --dport 53 -j ACCEPT
Once setup I logged into my pihole settings and went to the “Conditional Forwarding” section. I typed in the IP Address of the router and the Domain Name I assigned to the router. This enables the pihole to resolve DNS queries by hostname instead of the default by IP Address.
Takeaways and future thoughts:
Unexpected problems: Complicated setup with so-so documentation
Future Concerns: Future-proofing and updates will be fun
Future Enhancements: I expect much tinkering to ensue, I’m not even sure of all the capabilities
This project was almost completely done following the DD-WRT documentation and forums. All can be located here: https://dd-wrt.com/