NAT & Double NAT

NAT

There are 4 billion IP addresses are available in IPv4 (32 bits) network. If each person connect to the internet using individual IP address, the current IP addresses in IPv4 (4,294,967,296) is not enough. Network Address Translation (NAT) concept was introduced to solved this IP address issue.  The router get only one public IP address from ISP and all other connected devices gets the private IP address, it usually start with 192.168.0 or 10.0.0.  NAT converts all private IP address request and send outside the world using one public IP address.  With this, a home or an organization needs only one public address to connect the internet. Router are distributing private IP addresses using DHCP function.

DOUBLE NAT

Double NAT means multiple devices on the network are performing NAT functions. Example for this is, WiFi Routers are connected with the ISP Modem / Routers. It won’t prevent you to connect the internet, but sometimes it will create issues for VPN connections, accessing SSL websites, online games, and accessing other private network.

Solutions for Double NAT:

  • Enable Bridge mode in wireless router
    • Login to wireless router admin page in web-browser
    • Settings page, enable the bridge mode or disbale NAT and DHCP functions.
  • Set wireless router in modem’s DMZ
    • Login to wireless router admin page and find the WAN IP Address
    • Login to modem and go to DMZ settings.
    • Add wireless router, WAN IP address in DMZ settings.
  • Setup PPPoE between modem and wireless router
    • set PPPoE in wireless router.
    • PPPoE will bypass the NAT in the modem.

Router’s common issues

Routers are mandatory for small businesses and homes to connect the outside world.  Wireless routers are common for home and all types of businesses to get the internet connection to their desktops, laptops, smart phones, tablet devices and other wireless devices. Router determines how to send and where to send the information from one computer to another computer.  The information can be send from one network to another network as well.

Common issues of routers are:

  • Difficult configurations
  • Firmware updates
  • Hardware specs (Memory, HDD etc)
  • no. of simultaneous users

Common issues of Wireless routers are :

  • Interference (Positioning of router).
  • Distance between Wireless Access Points and client devices.
  • Router capacity for concurrent users.

Best ADSL Router

TP Link AC1750 Wireless Dual Band Gigabit ADSL2+ Modem RouterArcher D7

  • Supports Superfast Wireless Speed with 802.11ac standard
  • Dual band
  • 3 dual band detachable external antennas
  • Full Gigabit Wired Connection
  • One Gigabit LAN/WAN port
  • Three Gigabit LAN ports
                            
  • Simultaneous 2.4GHz 450Mbps and 5GHz 1300Mbps connections provide a premium wireless experience
  • Share a printer locally and files & media with networked devices or remotely via FTP server
  • Ethernet WAN (EWAN) port accepts connections from cable and fiber modems via Ethernet cable
  • TP-LINK Tether provides the easiest way to access and manage the router on your iOS and Android devices

Wireless Access Point Positioning

Placement of WiFi access point is most important in WiFi infrastructure design for optimizing nework.  It will reduce the hassle for IT staff after deployment of wireless access point setup.  Poor installation of WiFi will cause connectivity issue and lead to customer dissatisfaction.

The following tips helps to place a access points for better performance:

Free from obstacles

Try to place wireless access points without any obstacles such as wall, furniture, ceiling etc.  So that the Radio Frequency waves can be reach the client device faster speed.

Position

Access point placement on ceiling is best for horizontal coverage. If ceiling is too high try no to do. Do not put Access point above the ceiling tiles. It will create a extra barrier to go through the signal.

External antenna

Do not point external antennas all in one direction.

Interference

Avoid interference with the bluetooth devices, microwave ovens, fluorescent light bulbs, cordless phones, and other WLAN networks devices.

 

Hub vs Switch – Differences

Device Hub Switch
Layer Layer 1 device; Physical Layer Layer 2 device; Data link Layer
Device type Multiport repeater.

Pass all information received to all connected devices. It creates unnecessary traffic.

Network device.

Pass information only those devices need it. It avoids unnecessary traffic.

Network Use for smaller network Use for larger network
Function Connect a network, computers join in central hub Join multiple computers together within one local area network (LAN).
VLAN There is no VLAN function. VLAN can be created and security can be applied.
Broadcast One. One broadcast domain.

By default, do not breakup broadcast domain.

Forwarding Broadcast all connected devices. By default, do not forward packets to other networks like routers.
Bandwidth Provides less bandwidth. Provides more bandwidth.
Collision domain One.

Collision occurs commonly.

 

Many.

No collision occurs in full duplex switch.

Spanning Tree No Many
Duplex Half duplex Half / Full duplex
Ports Up to 12 ports Up to 48 ports
Speed Up to 10 Mbps Up to 10 Gbps

Switch

  • Layer 2 device; Data link Layer
  • Allow to connect multiple devices and port can be manged. Vlan can create & security can be apply.
  • Do not breakup broadcast domain by default
  • Do not forward packets to other networks like routers
  • Providing more bandwidth for LAN users
  • Only ‘Switch’ frames from one port to another within the switched network
  • Use hardware address to filter a network
  • Many collision domain
  • One broadcast domain

Hub

  • Layer 1 device; Physical Layer
  • To connect network, join through central hub
  • 1 Collision domain
  • 1 broadcast domain
  • Never full duplex
  • Multi-port repeater

How to reset Zyxel router ?

Reset Router

  1. Power on the router.
  2. Locate reset hole (It is usually appears back of the router, beside the power on/off switch).
  3. Push a pin or paper clip into the reset hole and hold it for 10 seconds (all LED lights will be flashed).
  4. Release the pin or paper clip from the hole.
  5. Wait for 2 to 3 minutes to complete the reset process. Once it is completed the router LED lights goes to steady mode.

Lights Indicator

  • Power    –  Green   –              Solid
  • LAN       –  Green   –              Flash when traffic is going through mode
  • DSL        –  Green   –              Solid
  • Internet –  Green   –              Flash when traffic is going through modem

How to setup Linksys router with a password?

Reset Router

  1. Power on the router.
  2. Locate reset hole (It is usually appears back of the router, beside the power on/off switch).
  3. Push a pin or paper clip into the reset hole and hold it for 10 seconds (all LED lights will be flashed).
  4. Release the pin or paper clip from the hole.
  5. Wait for 2 to 3 minutes to complete the reset process. Once it is completed the router LED lights goes to steady mode.

Login

Step 1: Open your browser (Firefox / Chrome/Internet Explorer / Safari)

Step 2: Type Linksys default IP address “192.168.1.1

Step 3: It prompts to type username and password.

Username: admin

Password: admin

Step 4: Click “OK

WiFi Settings

Step 5: Click “Wireless tab

Step 6: It brings to Configuration view – >Basic Wireless Settings.  Change the following configurations.

Select “Manual

Network mode: Mixed

                Network name (SSID):  <type your preferred name>

(It appears when you are connect to Wireless from your mobile)

SSID broadcast: Enabled

Step 7: Click “Save Settings

Step 8: It displays message as “Your settings have been successfully changed”.

Step 9: Click “Continue

Set Wireless Connection Password

Step 10: Click “Wireless Security” tab.

Step 11: Select Security mode as “WPA2 Personal

Step 12: Type wireless connection password. (Keep the password mixed with alphanumeric)

Step 13: Click “Save settings

Step 14: It display message as “Your settings have been successfully changed”.  Click “Continue”.

Set Linksys Router Password

Step 15: Click “Administration” tab and it brings to “Management” tab.

Step 16: Type your router password in “Router Password” and “Re-Enter to Confirm” boxes.

Step 17” Click “Save Settings

Note: Write down and keep your router password and wireless connection password in safe place.

How can I use my mobile 3G / 4G / Hotspot to provide internet access to my router?

Cradlepoint MBR1200B

This device solve your problem .  You can use your mobile hotspot to provide internet access to this device and access internet to your wired devices.  It helpful for small business or home users.

The Cradlepoint MBR1200B provides wired Ethernet, and 3G/4G wireless WAN connectivity to keep you and your business up and running.

Benefits:

  • Use as primary connection to the Internet with wired or wireless broadband.
  • Ensure against loss of productivity and business opportunity with automatic failover to 3G/4G when the wired connection is disrupted.
  • Load balance across the multiple wired and/or wireless connections when additional bandwidth is required.

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