H3C S7500 Series Ethernet Switches Operation Manual

Operation Manual – NAT, Netstream, Policy Routing
H3C S7500 Series Ethernet Switches Chapter 1
NAT Configuration
1-7
You can use the nat outbound command to associate an ACL with an address pool or
interface address. Different NAT modes need different configurations.
I. Configuring one-to-one NAT
Follow these steps to configure one-to-one NAT:
To do… Use the command… Remarks
Enter system view
system-view
—
Enter VLAN interface view
interface Vlan-interface vlan-id
—
Configure one-to-one
NAT
nat outbound acl-number
address-group group-number no-pat
slot slot-number
Required
The no-pat keyword indicates that only the source IP addresses in packets are
translated while the TCP/UDP port numbers remains unchanged. That is, NAT is based
on the one-to-one mapping between internal and external IP addresses.
II. Configuring NAPT
Follow these steps to configure NAPT:
To do… Use the command… Remarks
Enter system view
system-view
—
Enter VLAN interface view
interface Vlan-interface vlan-id
—
Configure NAPT
nat outbound acl-number
address-group group-number slot
slot-number
Required
Let’s compare the above two tables:
z In the first table, the configuration command uses the no-pat keyword. Only the IP
addresses of data packets will be translated while the port numbers remains
unchanged, that is, one-to-one NAT is implemented.
z In the second table, the configuration command does not use the no-pat keyword,
and so NAPT is enabled. Both IP addresses and port numbers of data packets will
be translated, that is, many-to-one NAT is implemented.
Caution:
An address pool used for NAPT cannot contain more than three addresses.