CHAPTE R
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Cisco Prime Network 4.0 User Guide
OL-29343-01
13
Monitoring Carrier Grade NAT Properties
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 fu ll-dup lex.
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 sup ports 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.
Carrier Grade NAT attributes and instances are configured as a CRS-ADVSVC-PLIM card on
Cisco CRS-1 routers. To route internal public addresses to external public addresses, a VPN Routing and
Forwarding (VRF) instance is created. Interfaces ar e created for the VRF at the subscriber-side (private)
and the Internet-side (public). The VRF enables static or dynamic routi ng of protocols on the interfaces.
Cisco 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 4.0.
The following topics describe how to use Prime Network Vision to view Carrier Grade NAT properties:
• User Roles Required to View Carrier Grade NAT Properties, page 13-2
• Viewing Carrier Grade NAT Properties in Logical Inventory, page 13-2
• Viewing Carrier Grade NAT Properties in Physical Inventory, page 13-5
• Configuring CG NAT Service, page 13-6