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NCOS: How to determine if you have a publicly routable IP address

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How to Determine if you have a Publicly Routable IP Address

This article applies to all Cradlepoint routers. It requires NCOS version 6.0.0 and higher.

 


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Summary
Troubleshooting
Related Articles


 

Overview

In order to remotely connect from the Internet into the Cradlepoint (or into devices connected behind it), it is necessary that the connection the Cradlepoint receives is publicly routable from the Internet. If the Cradlepoint is receiving a private (non-routable) IP address from a "network address translation" (NAT) router then (unless you have access to the NAT router to forward ports to the Cradlepoint's private IP address) you will not be able to route to it from the Internet.

Most wired (DSL, cable) Internet service providers provide (publicly routable) dynamic IP addresses by default, and usually offer (publicly routable) static IP addresses for an additional fee. The only difference between dynamic and static publicly routable IP addresses is that the dynamic IP address will change to a different address every time the modem connects.

It is common for users of dynamic public IP addresses to use a free or paid "Dynamic DNS" service to update a DNS record each time the address changes. This allows you to remember a host name rather than needing to know what your current WAN IP address is. For more information about how to set the Cradlepoint to use a dynamic DNS service, refer to this link: (http://knowledgebase.cradlepoint.com/articles/Support/setup-Dynamic-DNS-on-a-Series-3-CradlePoint)

These specific IP address ranges are reserved specifically as non-routable addresses to be used in private networks:

10.0.0.0 through 10.255.255.255
172.16.0.0 through 172.32.255.255
192.168.0.0 through 192.168.255.255

If the CradlePoint receives a WAN IP address within any of these private ranges, this means that connections originating from the Internet will not be able to get past the NAT router (without port forwarding) in order to actually reach the Cradlepoint's WAN interface.

In addition to RFC 1918 addresses above, cellular carriers may use addresses in the RFC 6598 space.
The RFC 6598 address space includes addresses from 100.64.0.0/10 to 100.127.255.255

Troubleshooting

These directions will walk you through verifying whether the Cradlepoint is receiving a publicly routable IP address, or if it is receiving a private IP address from a NAT router. This is determined by checking to see if the Cradlepoint's WAN IP address is the same address that other computers on the Internet see it as (indicating that you have a routable connection). If these addresses do not match, then your router is connecting behind a NAT router (which is the device that is actually connected to the Internet.

Series 3 Cradlepoint follow these steps:

  1. Log into the router's NCOS Page. For help with logging in please click NCOS: Accessing the Setup Pages of a Cradlepoint router.
  2. You should see the router Dashboard right away, but if you do not, select it from the navigation pane.

    User-added image

  3. Click your primary WAN interface to expand it.

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  4. Locate your IP Address. This is the

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  5. Now that you know the Cradlepoint's WAN IP Address, you will want to surf to an Internet website that indicates which IP address you appear to be connecting from. A few examples of sites that will show you this information are:

    User-added image

If the Cradlepoint's WAN IP Address is the same IP address that is shown at one of the sites above, then your router is getting a publicly routable IP address. This would mean that you should be able to use that connection to connect from the Internet to the Cradlepoint itself or to computers connected behind the Cradlepoint (if you are port forwarding to those devices).

If the Cradlepoint's WAN IP Address is not the same IP address that is shown at one of the sites above, then your router is getting a private non-routable IP address from your ISP's NAT router. The IP address shown from a site like http://www.whatismyip.com is the actual NAT router that you (and many other customers of that ISP) connect through. If you find that the Internet IP address does not match the Cradlepoint's WAN IP Address, you will want to contact your ISP to see if you can get a publicly routable IP address.
 

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TitleNCOS: How to determine if you have a publicly routable IP address
URL NameNCOS-How-to-determine-if-you-have-a-publicly-routable-IP-address

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