Concept of Dynamic DNS

A dynamic DNS service allows you to identify your PC with a domain name easy to remember, as instead of a strange type number  and be able to mount a server without complications regardless of whether or not we have a static IP.
An IP address is a set of 4 numbers from 0 to 255 separated by points, that identifies a computer on a network (a set of computers connected together). The same computer will be assigned an IP for each network to which it is connected.
Regardless of your Internet size it is evident from the above definition that all computer, by virtue of being connected to it, will have an IP for which it is known and referenced by other network devices. This IP must be different from another device's IPs of a local network that can assign itself, is given by the ISP.

So, why is useful a DDNS service?

The most common use of DDNS is remote access to IP, DVRs, NAS, routers, computers, tablets, cameras, smartphones and any device connected to Internet.

How can I Obtain a DDNS Service?

Some small applications called Automatic Update Client both with DDNS allow us to remotely access devices and files that are connected to the Internet and located in our home, office, etc. Some commercial routers has a module where you can set DDNS parameters, as in the case of D-Link routers, in fact,  the same company provides this service.

Who provides the DDNS service?

Many providers worldwide offer commercial or free Dynamic DNS service for this scenario. The automatic reconfiguration is generally implemented in the user's router or computer, which runs specific software to update the DDNS service. The communication between the user's equipment and the provider is not standardized, although a few standard web-based methods of updating have emerged over time.
Some companies like or provides free DDNS service. D-Link company offer this service only for their customers and the creation of a customer account is needed. This would be our first step to configure our router as a DDNS client.
Step 1: create an account on your preferred DDNS service provider, we choose D-Link (


Step 2: Once created the user and password you have to add a host. Maybe your DDNS service provider allows you to create several host for free.

Step 3: Once the host is created you have configure your router with your host name, user and password. In D-Link Model DIR-505 typing in a web browser the IP we can access the configuration software, then we can find this on the 'Maintenance' Tab, then 'Dynamic DNS' button

Step 4: Save the configuration and the router will reboot quickly, then, you have already your router configured as a Dynamic DNS host. If you want your PC routed as a server you have to configure this as a virtual server.

If you want to improve your WiFi connection, you have to perform some actions that influence on several factors important to WiFi Performance, ranging from changing the transmit power to change the transmission channel. In this article we will see how to configure your router taking as an example a D-Link DIR-505 model. However, the parameters to be modified are standard for any model or make of commercial router.

First we see some basic concepts to understand the nature of the optimal performance of a commercially available WiFi router for home.

Transmit Power

This is the power which the router uses to transmit any signal, normally any router operates at 100% power. However, in some cases, we have to isolate specific frequencies to a some area. We can do it by reducing the power of the radio, we can prevent interferences transmissions affecting beyond  corporate/home office or designated wireless area.

WMM Enable

Wireless Multimedia Extensions (WME), also known as Wi-Fi Multimedia (WMM), provides basic Quality of service (QoS) features to IEEE 802.11 networks. WMM prioritizes traffic according to four Access Categories (AC) - voice, video, best effort, and background. Enabling WMM can help control latency and jitter when transmitting multimedia content over a wireless connection.

Short GI

In telecommunications, guard intervals (GI) are used to ensure the different transmissions to not interfere with each other. The mode and the guard interval is an engineering decision depending on the topography  and implementation characteristics.

IGMP Snooping

IGMP snooping is to listen to the traffic generated by the network protocol IGMP (Internet Group Management Protocol). This feature allows network switches to 'hear' the conversation that occurs between routers and hosts. This allows too the switch to be capable of maintaining a map of the links that need multicast transmissions and thus handle the traffic so that only the ports need specific traffic to receive it. Some routers uses the IGMP protocol to support efficient multicasting -- transmission of identical content, such as multimedia, from a source to a number of recipients. This option must be enabled if any applications on the LAN participate in a multicast group.

WLAN Partition

Enabling WLAN Partition prevents associated wireless clients from communicating directly with each other.

Transmit Channel

The 802.11 workgroup currently works in 2.4 GHz bands and other frequencies.  This band is divided into a multitude of channels. Countries apply their own regulations to the allowable channels,  maximum power and range levels within these frequency. In some countries,  operators may use some of the channels at much higher power for long distance wireless access.
HT20/40 Coexistence
This refers to wideband of each channel. Enabling this option may prevent an undesirable interference of your device over your neighbors. Disabling can improve your connection speed.

Configuring your Router

As example, we are going to work on a D-LINK DIR-505 model, but almost all of these characteristics are available on any model or brand.
Here we can observe some of the previous mentioned characteristics, in the 'advanced' tab, then 'advanced wireless' at left bar. The decision of enabling/disabling these configuration options depends on what you really need, attending the above concepts and definitions.


You can change your transmit channel, but prior to do this you must be sure of what channel is less used in your neighborhood. For this you can use some software tools just like 'WIFI Radar' for Linux or WIFI Optimizer for Android.

WIFI Radar

This software lists your neighborhood WiFi Channel usage

WIFI Optimizer

This software plot all the channels and their usage

Based on this you can decide what channel to use, obviously, the less used channel is the recommendation.

In some cases, if you are experienced problems and  need to call ISP Support they can claim that everything is fine on their site and you will be stuck with your internal network problems. So, you as user may need be able to debug and fix certain network problems and it could be of a great help to you.

Common Network layout (topology)

First make sure that you know your network layout. Most probably it will be one of the following:

a) Modem -> Router (Cable+Wi-Fi) -> PC
b) Modem (Cable+Wi-Fi) -> PC
c) Modem ->  Switch -> Router (Cable+Wi-Fi) -> AP (Repeater)  -> PC

If router is not present in your network, it means that modem is working  as a router and it is important to know how to connect to modem administrative interface.
In Windows, to get some details about your network type ipconfig/all from cmd.exe launched under Administrative privileges. This command will show you lots of useful information about your network including address of the default gateway (for example we will use
In case of layout a) this address will be of your router. And in case of b) and c) it will be the modem address. 
In Linux, the equivalent command is ifconfig -a.

Check connection to default gateway

In Windows and Linux you can type the following command either in cmd.exe or Terminal emulator (Linux).


Instead of you should use default gateway address you got in previous step (ipconfig /all or ifconfig -a)
The replies (no errors) means that your computer can see modem or router without any problems.
When you use ping command you can see some parameters like the length of the packet, icmp_seq, time to life and time of response. There could have some three options:

  •     All the package received (0% packages lost)  what means that the connection is fine.
  •     Some packages received (0%<packages lost<100%) what it means there must be some interferences or other problems.
  •     All packages lost (100% packages lost) means that there is not connection between PC and router.

The time of response is important too what means the delay of receiving packages and is subject to interference, obstacles, among others..

Most commercial routers comes with an IP address,  username and password by default. Talking about the user and password, it is assumed that the user must change this setting to customize the security of their device. However, unfortunately many users never change the default password of the router which represents a security risk for home or office network.
In many cases, the user may forget the password for their router, then it may work the default password that was setup in factory. In case you can not remember the password then refer to the user manual which has details about how. As a last resort you can manually reset the router considering that this action will erase your custom settings, however, this action can also restore the default password which is the main theme of this mini tutorial.
Each manufacturer uses a different IP address, username and password for their devices. Here's a short list of most common commercial devices in more detailed way. It is not accurate or exhaustive, because it does not include all models of routers, but it covers many routers on the market. If the router is not here or the default password does not work, be sure to write following query in the search engine "... router default password". Note that for the time of publication of this document may have come on the market other devices which may have other configurations.
The default IP address/password for your router should be one of the following:

Following models (and brands) use the default IP Address (

Westell DSL Modems (US ONLY)

Some Linksys Routers/Modems

3Com Routers/Modems

Billion Routers/Modems

Netopia / Cayman Gateways

Following models (and brands) uses the other specific IP Address. 


Alcatel SpeedTouch Home/Pro – IP Address:  - (no default password)
Alcatel SpeedTouch 510/530/570 – IP Address:  - (no default password)


Asus RT-N16 – IP Address: - Default Password:  admin


Dell Wireless 2300 router – IP Address:


D-Link DSL-500 – IP Address: - Default Password: private
D-Link DSL-504 – IP Address: - Default Password: private
D-Link DSL-604+ – IP Address: - Default Password: private
D-Link DIR-505 – IP Address: - Default Password: private


Netcomm NB1300 – IP Address:
Netcomm NB1300Plus4 – IP Address:
Netcomm NB3300 – IP Address:
Netcomm NB6 – IP Address: - Default Username: admin -  Default Password: admin
Netcomm NB6PLUS4W – IP Address: Default Username: admin -  Default Password: admin -  Default WEP key: a1b2c3d4e5


Netgear DG814 – IP Address:
Netgear (Optus branded) IP Address:


Possible user and password combinations:
Username: admin
Password: admin

Username: Administrator
Password: admin

Username: admin
Password (empty password)

IP Address: