Enterasys Networks X-PeditionTM manual Multiple NAT Pools within an Interface

Configuring NAT Examples

3.Host 172.20.2.1 receives the packet and responds to address 200.2.2.1.

4.When the XSR receives the packet, it searches the NAPT table, using the protocol, global address and port, and translates the address to the inside local address 10.1.1.1 and destination port 1789, then forwards it to address 10.1.1.1.

Configuring NAPT

Enter the following commands to configure overloading of inside global addresses. This example configures an optional access list to permit specified traffic. All other traffic is implicitly denied.

XSR(config)#interface serial 1/0

+Configures serial port and acquires Interface mode

XSR(config-if<S1/0>)#ip nat source list 99 assigned overload

+Specifies NAT translation rules on the interface

XSR(config)#access-list 99 permit ip 10.1.1.0 0.0.0.255

+Adds ACL to permit IP traffic from the specified source

Multiple NAT Pools within an Interface

This scenario describes two NAT pools within interface F2. As shown in Figure 5-14, the pools are assigned to external port F2. One is used for packets sent to the 172.20.2.0 network and the other for the 164.17.2.0 network. Based n the ACL, outbound packets would use one of the two pools.

Note that the same internal host can have mappings in both pools since it could send packets to both destinations. Packets that do not match either ACL will be sent un-NATted.

Optionally, NAPT permits packets not matching either of the pool ACLs to pass through NAPT.

Figure 5-14 Multiple NAT Pools within Interface

Inside Outside

			Request			After Translation
		SA: 10.1.1.1				DA: 164.17.2.1
		DA: 172.20.2.1				SA: 200.2.2.1
	10.1.1.1
		Internal				External
		interface			XSR	interface
							F2
10.1.1.2							After Translation
							DA: 172.20.2.1
				NAT Table			SA: 200.2.2.1
			Inside local		Inside global
			IP Address		IP Address
	Request
			10.1.1.1		200.2.2.1
SA: 10.1.1.2
DA: 164.17.2.1			10.1.1.2		201.2.2.1

164.17.2.2

Internet

Reply
DA: 200.2.2.1	172.20.2.1
SA: 172.20.2.1

Multiple NAT pooling procedes as follows:

1.The user at 10.1.1.1 opens a connection to host 172.20.2.1.

XSR User’s Guide 5-41