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Block Of Public IPs and Disabling NAT 

 

The following document outlines how to disable the NB5580/w series NAT (Network Address Translation) 

feature in order to implement an additional block of public IP addresses.  

This type of setup is commonly used when you wish to individually assign a public IP address to a local 

computer or other TCP/IP enabled device(s) that are connected on the LAN side of the NB5580/w. This will 

then enable them to be publicly available and remotely accessible via the allocated public IP. Some 
examples of such computers or devices include Web Servers, Mail Servers, IPCameras etc. 

  

For this example we will use the following IP addressing information of which is usually provided by your 

ISP -  

 

=================================================  
Default WAN IP - 58.6.33.30 (ISP PPPoE/A assigned)  

/29 Block of public IP addresses  

Network IP Address: 58.6.33.32  

Useable IP Range: 58.6.33.33 – 58.6.33.38  

Broadcast IP Address: 58.6.33.39  

Subnet Mask: 255.255.255.248  
=================================================  

 

Note:- For this feature to be available your modem should be installed with firmware version 

1.05.02 and above. 

 

1.

 

Reset The NB5580/W back to factory defaults by holding down the reset button (Back of unit) for 
10 seconds. 

2.

 

Login to the NB5580/w web-based interface i.e http://192.168.1.1 and if prompted, enter the 

default username and password of “admin” for both.  

3.

 

You will first need to setup your Modem to connect to your ISP using the “PPP Unnumbered” option 

with “static IP” selection. To do this change the Wan Type at on the ‘One Page setup” to IP 
Unnumbered over PPPoE, 
and change the selection to Fixed IP. Simply fill out your complete 

ISP username and password in the required (you do not require a service name). . To save the 

changes click on the “Apply” button. 

4.

 

The first Public IP address from your block should be assigned as the LAN IP address of the 

Modem. This will ensure that you are still able to manage the connection when the subnets have 

been changed on the rest of the network. This can be done by updating the LAN IP address and 
subnet Mask on the one Page setup. To save the changes click on the “Apply” button. 

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