Converting a DD-WRT Router to Wireless Access Point: Step-by-Step Configuration Guide for Network Extension

Before reconfiguring your Linksys router with DD-WRT firmware as an access point, ensure:

Primary router handles DHCP (e.g., 192.168.1.1)
DD-WRT router has stable firmware (v3.0 or later recommended)
Ethernet cable for backhaul connection
Admin access to both routers

The ideal deployment places the access point where it can extend coverage without channel interference. For dual-band routers:

Primary Router (2.4GHz: Ch6, 5GHz: Ch36)
   │
   └── DD-WRT AP (2.4GHz: Ch11, 5GHz: Ch149)

Step 1: Reset to Factory Defaults
Navigate to Administration > Factory Defaults and click "Reset Router" to clear previous configurations.

Step 2: LAN IP Assignment
Set a static IP within your primary router's subnet but outside DHCP range:

Navigation: Setup > Basic Setup
- Local IP Address: 192.168.1.2
- Subnet Mask: 255.255.255.0
- Gateway: [Primary Router IP]
- Local DNS: [Primary Router IP]
- Disable DHCP Server

Step 3: Wireless Configuration
Configure matching security settings with your main network:

Navigation: Wireless > Basic Settings
- Wireless Mode: AP
- SSID: [Match primary network or set extension]
- Channel: Manual selection (non-overlapping)
- Wireless Security: WPA2 Personal AES
- Shared Key: [Primary network password]

For performance optimization in congested areas:

# SSH into DD-WRT and adjust TX power
nvram set wl0_txpwr=50
nvram set wl1_txpwr=50
nvram commit
reboot

# Optional: Enable beamforming for n/ac devices
nvram set wl0_txbf=1
nvram set wl1_txbf=1

After applying changes, verify:

Client devices seamlessly roam between APs
iperf3 tests show consistent throughput (>50Mbps for n-standard)
No IP conflicts in DHCP leases

For enterprise environments, consider adding these NVRAM parameters:

nvram set wl0_ap_isolate=0       # Disable client isolation
nvram set wl0_wme=1              # Enable WMM QoS
nvram set wl0_plcphdr=long       # Better compatibility

When integrating a DD-WRT flashed router as an access point, we're essentially converting a routing device into a layer 2 network bridge. This is particularly useful when you already have a primary router handling DHCP/NAT/firewall duties, and need to extend wireless coverage.

First, connect your secondary router (the DD-WRT device) to your primary router using an Ethernet cable:

Primary Router LAN Port → DD-WRT Router LAN Port

Important: Do not use the WAN port on the DD-WRT device. This maintains the layer 2 bridging functionality we need.

Access your DD-WRT web interface (typically at 192.168.1.1) and follow these steps:

1. Disable DHCP Server

Setup → Basic Setup → Network Address Server Settings (DHCP)
Set DHCP Server to "Disabled"

2. Assign Static IP

Setup → Basic Setup → Network Setup → Router IP
Set Local IP Address to an unused IP in your primary network's subnet
(e.g., if primary router is 192.168.1.1, use 192.168.1.2)
Set Subnet Mask to match primary router (typically 255.255.255.0)
Set Gateway to primary router's IP

3. Configure Wireless Settings

Wireless → Basic Settings
Set Wireless Mode to "AP"
Set Wireless Network Mode to match your devices (e.g., "NG-Mixed")
Set SSID (can match primary router for seamless roaming)
Set Security Mode and Key (match primary router settings)

Wireless → Wireless Security
Configure WPA2 Personal with AES encryption (recommended)

4. DNS Configuration

Setup → Basic Setup → Network Setup → Static DNS
Set DNS servers (use your primary router's IP or public DNS like 8.8.8.8)

For more complex setups, you can create VLANs to segregate traffic:

Setup → Networking → VLANs
Create new VLAN ID (e.g., 10 for main network, 20 for guest)
Assign ports to VLANs

After applying changes:

Connect a device to the new access point
Verify you receive an IP from the primary router's DHCP
Confirm internet connectivity
Run traceroute to ensure traffic flows through primary router

For administrators who prefer CLI configuration, here's the equivalent shell commands:

nvram set lan_proto=static
nvram set lan_gateway=192.168.1.1
nvram set lan_ipaddr=192.168.1.2
nvram set dhcpd_start=
nvram set dhcpd_end=
nvram commit
reboot

Double NAT detection: If devices show "Double NAT" warning, ensure WAN port is disconnected and DHCP is disabled.

IP conflicts: Verify no other devices use the static IP assigned to the access point.

Wireless isolation: Check "AP Isolation" is disabled unless you specifically want client isolation.

For best results with 802.11n devices:

Wireless → Advanced Settings
Set Channel Width to 40MHz (if minimal interference)
Enable Frame Burst
Set TX Antenna to 3 (if 3x3 router)
Set Beacon Interval to 100
Set DTIM Interval to 3