Chapter18 Network Address Translation
Network Address Translation Rules
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Cisco Router and Security Device Manager Version 2.2 User’s Guide
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Rule Type
Rules are either static address translation rules or dynamic address translation
rules.
Static address translation allows hosts with private addresses to access the
Internet and to be publicly accessible from the Internet. It statically maps one
private IP address to one public or global address. If you wanted to provide static
translation to 10 private addresses, you would create a separate static rule for each
address.
Dynamic address translation. There are two methods of dynamic addressing
using NAT. One method maps multiple private addresses to a single public address
and the port numbers of host sessions to determine which host to route returning
traffic to. The second method uses named address pools. These address pools
contain public addresses. When a host with a private address needs to establish
communication outside the LAN, it is given a public address from this pool. When
the host no longer needs it, the address is returned to the pool.
Clone selected entry on Add
If you want to use an existing rule as the basis for a new rule that you want to
create, select the rule and check this box. When you click Add, the addresses in
the rule you selected appear in the Add Address Translation Rule window. You
can edit these addresses to get the ones you need for the new rule instead of typin g
the entire address into each field.
What do you want to do?
If you want to: Do this:
Designate the inside and outside
interfaces.
You must designate at least one inside
interface and one outside interface in
order for the router to perform NAT.
Click Designate NAT interfaces, and designate interfaces as
inside or outside in the NAT Interface Setting window.
Interfaces can also be designated as inside or outside
interfaces in the Interfaces and Connections window.
Add, edit, or delete an address pool.
Dynamic rules can use address pools to
assign addresses to devices as they are
needed.
Click Address Pools, and configure address pool information
in the dialog box.