Symantec Security 5600 Series, Security 5400 Series,Clientless VPN 4400 Series, Administration Manual

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670 Field descriptions
Assets field descriptions
Address Transform Properties—Source Address Transform tab
The Source Address Transform tab lets you specify how the source address is transformed.
Associated tasks
The task that you can perform with this tab is:
■
“Configuring address transforms” on page 360
Address Transform Properties—Description tab
Optionally, provides an extended description. This information is useful to help track changes or it can
be used as criteria for searches.
The maximum length is 20,000 alphanumeric characters.
NAT pools
A network address transform (NAT) pool is a set of addresses that are designated as replacement
addresses for client IP addresses. You use NAT pool addressing to present a routable address to the
security gateway. This is commonly done to translate packets on non-routable networks to routable
packets for travel across public networks, or to hide external source packets and make them appear to
be internal source packets. NAT helps to guarantee that return traffic is routed back to the appropriate
security gateway.
NAT pools do not time out. As long as the connection is active, the client owns the allocated address. If
the NAT pool is being used in a VPN tunnel, the tunnel itself can time out, based on the parameters
defined. When this happens, the connection is dropped, and the NAT address is released back into the
pool.
The security gateway translates source addresses for transmitted packets and destination addresses
for received packets. NAT substitutes the source IP address of the incoming packets with an address
from the assigned pools. The security gateway maintains a table of the pairings so that return traffic is
switched back to the original IP address.
Dynamic NAT Pool Properties—General tab
You use the dynamic NAT pool properties dialog box to map a client IP address to an IP address that is
dynamically chosen from a pool of addresses. You must use a range of addresses reserved in RFC 1918.
These non-routable Internet address ranges are inclusive and include:
■
10.0.0.0 through 10.255.255.255
■
172.16.0.0 through 172.31.255.255
■
192.168.0.0 through 192.168.255.255
Table D-118
Address Transform Properties—Source Address Transform tab
Field Description
Use gateway address The real packet source address is overwritten by the security gateway address for the
connection.
Use original source
address Prevents the security gateway from overwriting the real source address for the connection,
effectively applying source side transparency to the connection.
This option is selected by default.
Use NAT pool Applies a configured NAT pool addressing scheme to a VPN tunnel or non-tunneled
connection. The drop-down list displays NAT pools from which you can choose.