Tip
This is the documentation for the 22.06 version. Looking for the documentation of the latest version? Have a look here.
NAT Modes¶
There are two NAT modes supported by TNSR, configured by the following command:
tnsr(config)# nat global-options nat44 endpoint-dependent (true|false)
- false:
Endpoint-independent NAT mode. The default NAT mode. Formerly known as “simple” NAT mode. Holds less information for each session, but only works with outbound NAT and static mappings.
- true:
Endpoint-dependent NAT mode. Uses more information to track each session, which also enables additional features such as
out-to-in-onlyandtwice-nat.
Note
There must be at least one inside and outside interface for NAT to
function, see Network Address Translation and Outbound NAT for more details.
Warning
The mode cannot be changed while NAT is enabled. Disable NAT before running this command (Enable NAT).
Endpoint-independent NAT¶
Endpoint-independent NAT is the most basic NAT mode. It tracks sessions in a hash table using four items:
Source IP address
Source port
Protocol
FIB table index
Endpoint-dependent NAT¶
Endpoint-dependent NAT mode tracks more information about each connection. As suggested by the name, the key difference is in tracking the destination of the connection:
Source IP address
Source port
Target IP address
Target port
Protocol
FIB table index
Some NAT features require this extra information, notably out-to-in-only and
twice-nat.