Configuration Examples - Foundry Networks Switch and Router Installation And Configuration Manual

Foundry Switch and Router Installation and Configuration Guide

Configuration Examples

This section shows two complete configuration examples for NAT. The examples are based on different network
topologies.
• NAT clients connected to the Layer 3 Switch by a Layer 2 Switch.
• NAT clients connected directly to Layer 3 Switch ports.
NOTE: You also can enable the feature on the primary port of a trunk group, in which case the feature applies to
all the ports in the trunk group. These examples do not show this configuration.
Private NAT Clients Connected to the Layer 3 Switch by a Layer 2 Switch
Figure 20.2 shows an example of a NAT configuration in which the clients in the private network are attached to
the Layer 3 Switch through a Layer 2 Switch.
Outside NAT interface
Port 4/1
63.251.295.46/26
Inside NAT interface
Port 1/24
10.10.10.50/26
Figure 20.2 NAT clients connected the Layer 3 Switch by a Layer 2 Switch
Here are the CLI commands for implementing the NAT configuration shown in Figure 20.3. These commands
configure the following:
• An IP address and default gateway on the Layer 2 Switch
• An Access Control List (ACL) for the range of private addresses in the private network on virtual interface 10
• A Pool of public (Internet) address to use for translation of the private addresses
• An association of the ACL for the private addresses with the pool for translation
• A default route that has the Internet access router as the route's next-hop gateway
The commands also enable inside NAT and outside NAT on the ports connected to the private network's Layer 2
Switch and to the Internet access router, and save the configuration changes to the startup-config file.
20 - 14
Internet
Internet
access router
63.251.295.1/26
The switching router performs
NAT for traffic between the
outside NAT interface and the
inside NAT interface.
NAT Pool = 63.251.295.47/26 - 63.251.295.48/26
10.10.10.3
10.10.10.2 10.10.10.5 10.10.10.6
Link Link
Activity Activity
Console
Power
10.10.10.4
10.10.10.7
10.10.10.49/26
December 2000