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A tutorial of using DD-WRT firmware in routers

Router and firmware

A router, good or bad, always has official firmware installed. The functionality of the official firmware may be powerful, stable and easy to use, or buggy, weak and hard to use. That is totally depending on who made it and what hardware it has. The hardware of a router is fixed and hard to be replaced and/or changed while the firmware of a router can be changed and replaced based what hardware it has. In the market, there are a number of customized alternative firmware available for a lot of modes and brands of routers, such as DD-WRT, OpenWRT, X-WRT, Gargoyle, tomato, RouterTech, oleg and so on. By flashing a router with an alternative firmware, the router’s functionality can be dramtically improved, such as user/application access and additional functionality, almost at all time surpassing the capabilities of the original device. For example, a series of Linjsys routers can be flashed with DD-WRT firmware. Actually the first alternative firmware of routers were developed around LinkSys routers.

DD-WRT

DD-WRT is Linux-based firmware for wide range of ieee 802.11a/b/g/h/n wireless routers based on a Broadcom or Atheros chip reference design. It covers brands like Linksys, Asus, D-Link, Netgear and many brands you never knows. Since DD-WRT is so well developed and documented, it comes pre-installed with routers manufactured by Buffalo Technology and a few others.

Among features not found in the original Linksys firmware, DD-WRT adds the Kai Daemon for the Kai Console Gaming network, WDS wireless bridging/repeating protocol, Radius Authentication for more secure wireless communication, advanced Quality of Service controls for bandwidth allocation, software support for the SD-Card hardware modification, and a lot more. You can find official definition of the DD-WRT firmware at What is DD-WRT?.

Here I will not discuss how to install DD-WRT firmware to your wireless router. Please visit dd-wrt.com and search the router database. After you find specific information about your router, you should follow the instructions on the site to flash your router with the alternative firmware.

Connection to internet

In the Setup page of the DD-WRT firmware, you can find a section related to WAN Connection Type. There are multiple selections of the connection types: Static IP, Automatic Configuration – DHCP, PPPoE, PPTP, L2TP, and HeartBeat Signal. To select which connection type, that totally depends on your ISP provider. Please refer to their instructions when you setup your router. In my situation, I just use the default option, Automatic Configuation – DHCP. My ISP provider is MediaCom high speed cable internet service.

DHCP setup

Every router has default setting for the DHCP server. You can set the start IP address and maximum DHCP users in your LAN. One important setting is the static DNS servers. You can provide three static DNS server. I use my router as the first and OpenDNS NDS server (208.67.220.220) as the second and then Google Free DNS server (8.8.8.8) as the last. See the following screen shot for reference.

Time settings

One of very useful setting is the time settings. I enable NTP client and set the correct Time Zone and Summer Time (DST). We need provide a NTP server for The Server IP/Name. There are a lot of free NTP servers available. I choose “pool.ntp.org”, which is a big virtual cluster of timeservers providing reliable easy to use NTP service for millions of clients.



Use dynamic DNS

In the DDNS tab, you can setup automatic DDNS service update. In case you do not know what is DDNS. All home networks hook to public network through internet providers, either cable high speed internet service or phone line high speed internet service or others. One public IP address is assigned to a home network LAN. This IP address is not fixed and always change. If you want to access your network from internet, outside of your LAN. It is the IP address you need. Since it is always changing, how can we keep track of it. That is where DDNS service come in to play. By using router’s function related to DDNS, router will automatically call the DDNS service and update the currect IP address whenever it is changed. This is neat service and allow you running web server in your LAN and server the world. The following screen shot demonstrate the DynDNS service. The hostname is the domain you chose in the DynDNS.org.

Wireless Security

We you are running a wireless router at home, you always want to secure your wireless signal. Otherwise you provide other people to utilize your internet service and expose your home network to potential security issue. There are a lot of selection, you can choose what is suitable to you. The screen shot demonstrate WPA personal security method I used. You can find this in Wireless -> Wireless Security.

Port Forwarding

As I mentioned that you can run web server in your LAN and serve the world. To achieve this is pretty simple.  Choose NAT/QoS -> Port forwarding. Click Add button to add an application to the port forwarding table. Here is am example of adding http web service to the table. Once this setting is complete, you can visit your LAN web server all over the world with no restriction. Is it neat? I think so.  In addition to web service, you can add FTP, mail, and all other service based on your needs.

Use LAN port as WAN port and vice versa

Sometimes, we have a need to switch WAN port to LAN port or vice versa. One situation I can think of is the WAN port is broken and you need switching one LAN port to WAN for internet connection. In the following screen shot, you can see all LAN ports 1,2,3,4 are set in VLAN 1 and WAN port is set in VLAN 2. If you need switch one of LAN port to WAN port, just uncheck one of PORT 1-4 in VLAN 1 and check it in VLAN 2 and do corresponding setting. You can achieve your goal.

Traffic monitoring

One very useful feature of DD-WRT provides is network monitoring. You can find it at Status -> Bandwidth page. There are three graphs: LAN, WAN, and WLAN. See the following screen shot. I always use this function to monitor the network activity and detect any problem in my network.

Anyway, DD-WRT alternative firmware is an very nice and stable firmware I ever used. When I use Linksys router, I used it. After I upgraded my router to ASUS gigabit router, I still use it. I love the functions and flexibility of DD-WRT firmware provides. Even though I only explored a few functions it provides, I know it has more functions and I can switch them on when I need them.

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