MNET Services>Telecom Data Networking>>Private Address Space Policy (RFC 1918/net 10)


This policy applies in any cases where there is a need or request to assign private or non-routed blocks of address space directly to an interface of an MNET device, via a route, or either the inside or outside addresses when NAT is used.

It does not apply to any use by MNET customers or others when the use does not involve any MNET devices.

Private Ranges

RFC 1918 and other documents define the following private address blocks. These blocks are guaranteed to not be routed across the Internet.

networkrangenotes to Class A to Class B to Class B to Class C


MNET has designated portions the private address space blocks as managed. The managed blocks are:

networkrangenotes to Class B to Class B to Class B to Class B

A managed network has these properties:

  • Its assignment is made by MNET and tracked in MNET's management systems.
  • Assignments follow the same procedures as any other network blocks.
  • It will not be used in more than one place within MNET.
  • Addresses in this range may be entered into MNET's DNS servers.
  • Reverse address lookup will be available for addresses in this range. However, you must use MNET's DNS servers for reverse lookup.
  • It may not be routed across MNET at all, may be routed over only a portion of MNET, or may be routed across all of MNET.
  • It will never be routed outside of MNET.

Non-Routed Networks

In order to meet specific customer needs, MNET may elect to not route some network blocks across MNET. Normally, these blocks will be in the private ranges outlined above. The specifics are negotiated between MNET and the customers.

Existing Customer Use

Existing customers usage (on or before October 2003) is not directly affected by this change.

MNET will continue existing assignments of network addresses as interface addresses, routed blocks (via customer interfaces) or inside NAT addresses. These assignments will be made only on MNET "leaf" devices, i.e., those MNET devices that do not take part in dynamic routing protocols.

The assignments for all customers within any given chain of leaf devices (i.e., are off the same non-leaf device interface) will be coordinated. MNET may still use addresses outside of the customer use range for designating the device itself and other purposes.

MNET will not record or track the customer assignment of network blocks in the customer use range outside of the device configuration. MNET will not enter such customer addresses in this range into its DNS servers.

Customers with existing private address space usage will be affected when they start interacting with hosts in private address space usage whose assignments conflict with the customer use. For example, if a customer is using as a workstation and for a server, the customer will be affected if they wish to use another customer's server at an MNET-assigned address.

Customers may also be affected if another customer in the chain of leaf devices needs access to such addresses.

In particular, customers will be affected if they use the MNET voice over IP telephony system or are accessing the EUCC system (which includes Enterprise Email).