Cisco Prime Network User Guide, 5.1

Monitoring Carrier Grade NAT Configurations

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Carrier Grade NAT is a large-scale Network Address Translation (NAT) that provides translation of millions of private IPv4 addresses to public IPv4 addresses. These translations support subscribers and content providers with a bandwidth throughput of at least 10 Gbps full-duplex.

Carrier Grade NAT addresses the IPv4 address completion problem. It employs Network Address and Port Translation (NAPT) to aggregate many private IPv4 addresses into fewer public IPv4 addresses. For example, a single public IPv4 address with a pool of 32,000 port numbers supports 320 individual private IP subscribers, assuming that each subscriber requires 100 ports. Carrier Grade NAT also offers a way to implement a graceful transition to IPv6 addresses.

To route internal public addresses to external public addresses, a VPN Routing and Forwarding (VRF) instance is created. Interfaces are created for the VRF at the subscriber-side (private) and the Internet-side (public). The VRF enables static or dynamic routing of protocols on the interfaces.

Prime Network supports the following instances for Carrier Grade NAT:

• Stateful Address Translation- NAT44 Stateful
• Stateless Address Translation- NAT 64 Stateless (X-LAT)
• IPv6 rapid deployment (6rd)

Each Carrier Grade NAT instance has several attributes listed under them, such as preferred location, address pools, associated interfaces, and statistics. The attributes are grouped under related categories. The categories and attributes are listed below:

Note IPv4 Network Address Translation (NAT44) is not supported for devices running Cisco IOS XR software version 4.1.

For information on the devices that support Carrier Grade NAT, refer to Cisco Prime Network 5.0 Supported VNEs.

The following topics describe how to use the Vision client to view Carrier Grade NAT properties. If you cannot perform an operation that is described in these topics, you may not have sufficient permissions; see Permissions for Managing Carrier Grade NAT.

• Viewing Carrier Grade NAT Properties in Logical Inventory
• Viewing Carrier Grade NAT Properties in Physical Inventory
• Configuring a CG NAT Service

Viewing Carrier Grade NAT Properties in Logical Inventory

To view Carrier Grade NAT properties in logical inventory:

Step 1 In the Vision client, double-click the Cisco CRS device configured for Carrier Grade NAT.

Step 2 In the Inventory window, click Logical Inventory > Carrier Grade NAT.

The Carrier Grade NAT properties are displayed in logical inventory as shown in Figure 20-1.

Figure 20-1 Carrier Grade NAT in Logical Inventory

Table 20-1 describes the Carrier Grade NAT properties that are displayed.

You can also display pool utilization by right-clicking a VNE and choosing Commands > Show > Pool Utilization.

Viewing Carrier Grade NAT Properties in Physical Inventory

To view Carrier Grade NAT properties in physical inventory (in this example, a Cisco CRS device):

Step 1 In the Vision client, double-click the Cisco CRS device.

Step 2 To view Carrier Grade NAT properties configured on a specific interface, click Physical Inventory > chassis > shelf > slot > card > interface. See Drilling Down Into a Port’s Configuration Details (Including Services and Subinterfaces) for a description of the information displayed in the Subinterfaces table.

Step 3 To view Carrier Grade NAT properties configured on a Cisco CRS-CGSE-PLIM card, click Physical Inventory > chassis > shelf > slot > PLIM-card. Figure 20-2 shows an example of Carrier Grade NAT properties in physical inventory.

Figure 20-2 Carrier Grade NAT Properties in Physical Inventory

The field CGN Service is displayed, and the entry is hyperlinked to the associated Carrier Grade NAT service in logical inventory.

Configuring a CG NAT Service

The following CG NAT commands can be launched from the inventory by right-clicking the appropriate node and choosing Commands > Configuration. Your permissions determine whether you can run these commands (see Permissions for Managing Carrier Grade NAT). To find out if a device supports these commands, see the Cisco Prime Network 5.1 Supported Cisco VNEs.