User's Manual

UTT Technologies Chapter 8 NAT
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Weight. In this case, the NAT sessions initiated from the same IP address will use the
same NAT rule, that is, a LAN host will use only one NAT rule to access the Internet.
For example, there are three EasyIP NAT rules whose Weights are 3, 2 and 1
respectively. Then in the sequence of accessing the Internet, the first, second and third
free hosts will use the first rule, the fourth and fifth free hosts will use the second rule, the
sixth free hosts will use the third rule; then the seventh, eighth and ninth free hosts will use
the first rule ... and so on.
2. Load Balancing Based on NAT Session
If you choose NAT session as the load balancing policy, the Device will assign the NAT
sessions to each EasyIP NAT rule in turn. The ratio of the numbers of the NAT sessions
assigned to each EasyIP NAT rule is the same with the ratio of each rule¶s Weight. In this
case, the NAT sessions initiated from the same LAN host will use different NAT rules, that
is, a LAN host will use several NAT rules to access the Internet.
For example, there are three EasyIP NAT rules whose Weights are 3, 2 and 1
respectively. Then in the sequence of accessing the Internet, the first, second and third
NAT sessions initiated from the free LAN hosts will use the first rule, the fourth and fifth
NAT sessions will use the second rule, the sixth NAT sessions will use the third rule; then
the seventh, eighth and ninth NAT sessions will use the first rule ... and so on.
3. How to Choose the Load Balancing Policy
In most cases, it is suggested that you choose IP address as the load balancing policy. If
you want to use some applications that need high bandwidth, such as the NetAnts,
FlashGet, Net Transport, and other multi-threaded download managers (multi-threaded
download means that it can split a file into several pieces and download the pieces
simultaneously, and merge them together once downloaded), you may choose NAT
session as the load balancing policy to take full advantage of multiple Internet connections¶
bandwidth to increase download speed. Note that even you choose NAT session as the
load balancing policy, due to that the related download website is busy or there are some
other reasons, the bandwidth of each Internet connection cannot be aggregated fully, so
some applications may be not running smoothly.
8.3.2.5 The Priorities of NAT Rules
When receiving a request packet initiated from a LAN host to access the Internet, the
Device will firstly search the NAT Rule List to find out if there is a NAT rule matching the
source IP address or the packet, that is, the host¶s IP address belongs to the address
range specified by the Start Internal IP Address and End Internal IP Address of the
NAT rule. If a match is found, the Device will assign the matched NAT rule to the host, and
then the host will use this rule to access the Internet. Else, the Device will assign the
EasyIP NAT rule to the host. If there are several EasyIP NAT rules, the Device will assign