Installation guide

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Device Manager Guide, Cisco ACE 4700 Series Application Control Engine Appliance
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Chapter 10 Configuring Network Access
Configuring VLAN Interface NAT Pools and Displaying NAT Utilization
Configuring VLAN Interface NAT Pools and Displaying
NAT Utilization
You can configure Network Address Translation (NAT) pools, which are designed to simplify and
conserve IP addresses. A NAT pool allows private IP networks that use unregistered IP addresses to
connect to the Internet. NAT operates on a router, usually connecting two networks, and translates the
private (not globally unique) addresses in the internal network into legal addresses before the packets
are forwarded to another network.
In addition to creating a NAT pool, you can display the utilization information associated with it.
This section includes the following topics:
• Configuring VLAN Interface NAT Pools, page 10-32
• Displaying NAT Pool Utilization, page 10-33
Configuring VLAN Interface NAT Pools
This procedure shows how to configure NAT pools for a VLAN interface.
Guidelines and Restrictions
• The ACE Appliance Device Manager allows you to configure NAT so that it advertises only one
address for the entire network to the outside world. This effectively hides the entire internal network
behind that address, thereby offering both security and address conservation.
• Several internal addresses can be translated to only one or a few external addresses by using Port
Address Translation (PAT) in conjunction with NAT. With PAT, you can configure static address
translations at the port level and use the remainder of the IP address for other translations. PAT
effectively extends NAT from one-to-one to many-to-one by associating the source port with each
flow.
• When server load balancing is IPv6 to IPv4 or IPv4 to IPv6, you must configure source NAT.
Prerequisites
At least one VLAN interface is configured on the ACE (see Configuring Virtual Context VLAN
Interfaces, page 10-10).
Procedure
Step 1 Choose Config > Virtual Contexts > virtual_context > Network > NAT Pools.
The NAT Pools table appears.
Step 2 In the NAT Pools table, click Add to add a new entry. The NAT Pool configuration screen appears.
Step 3 Select the VLAN interface you want to configure a NAT pool.
Step 4 In the NAT Pool Id field, either accept the automatically incremented entry or enter a new number to
uniquely identify this pool. Valid entries are integers from 1 to 2147483647.
Step 5 For the IP Address Type, select either IPv4 or IPv6.
Step 6 In the Start IP Address field, enter an IP address for the selected IP Address Type. This entry identifies
either a single IP address or, if using a range of IP addresses, the first IP address in a range of global
addresses for this NAT pool.