3Com 3CR990-FX-97 Configuring IPSec Offloads, Configuring Offloads for a Group of Different NICs

4Using Windows Offload Features

The following table describes values for the offload functions:

Value	Offload Function Enabled
All Offloads Disabled	No offloads
cksum	TCP Checksum
cksum-ipsec	TCP Checksum and IPSec
cksum-tcpseg	TCP Checksum and TCP Segmentation
cksum-tcpseg-ipsec	TCP Checksum and TCP Segmentation and IPSec
ipsec	IPSec
tcpseg	TCP Segmentation
tcpseg-ipsec	TCP Segmentation and IPSec

Configuring Offloads for a Group of Different NICs

Your computer may contain a combination of installed NICs (including one or more 3Com 3CR990-FX-97 NICs with varying offload capabilities. If you have a mix of dissimilar NICs configured in a group, then 3Com DynamicAccess Advanced Server software supports only those offload functions that are supported by all the NICs in the group.

For example, if you have created a group consisting of a 3CR990-FX-97 NIC and another NIC that does not have any offload capabilities, then the group does not support any offloads.

In another example, if you have a group of three NICs with two supporting TCP Checksum, TCP Segmentation, and IPSec offloads, and one supporting only IPSec, then the group supports only IPSec offloads.

If you add a NIC to an existing group, and that NIC has offload capabilities that differ from those of the group, then you must reconfigure the group: that is, you must delete the group, recreate the group, and restart the computer. (If you do not delete and recreate the group, the Advanced Server software does not bind to the NIC.)

Similarly, if you replace a NIC that has been configured as part of a group with another

NIC that has different offload capabilities, then you must reconfigure the group.

In addition, if you disable or enable any offloads for a group through the Windows 2000

Advanced tab, then you must reconfigure the group.

Configuring IPSec Offloads

The 3CR990-FX-97 NIC performs data-encryption-processing offloads in Windows 2000 and Windows XP environments. The 3CR990-FX-97 NIC does not actually encrypt the data: the operating system performs that function.

Encryption processing is handled entirely by the 3XP processor on the NIC. The 3XP processor enables true end-to-end network security at the data capacity of the connected network cable without sacrificing performance.

Internet Protocol Security (IPSec) is a framework of open standards for ensuring secure private communications over IP networks. IPSec ensures confidentiality, integrity, access control, and authenticity of data communications across a public IP network.

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