Intel PCI User Manual
Receive and Transmit Description
Software Developer’s Manual
33
Table 3-6. 82544GC/EI Supported Receive Checksum Capabilities
lists the general details about what packets are processed. In more detail, the packets are
passed through a series of filters (
through
) to determine if a receive
checksum is calculated.
Note: (
through
) does not apply to the 82544GC/EI.
3.2.9.1
MAC Address Filter
This filter checks the MAC destination address to be sure it is valid (IA match, broadcast,
multicast, etc.). The receive configuration settings determine which MAC addresses are accepted.
See the various receive control configuration registers such as RCTL (RTCL.UPE, RCTL.MPE,
See the various receive control configuration registers such as RCTL (RTCL.UPE, RCTL.MPE,
RCTL.BAM), MTA, RAL, and RAH.
IPv4 Packet has IP options
(IP header is longer than 20 bytes)
(IP header is longer than 20 bytes)
Yes
Yes
Packet has TCP or UDP options
Yes
Yes
IP header’s protocol field contains a
protocol # other than TCP or UDP.
protocol # other than TCP or UDP.
Yes
No
a. The IPv6 header portion can include supported extension headers as described in the IPv6 Filter
section.
b.For the 82541xx and 82547GI/EI, frame sizes greater than 2 KB require full-duplex operation.
section.
b.For the 82541xx and 82547GI/EI, frame sizes greater than 2 KB require full-duplex operation.
Table 3-5. Supported Receive Checksum Capabilities
Packet Type
HW IP Checksum
Calculation
HW TCP/UDP Checksum
Calculation
Packet Type
HW IP Checksum
Calculation
HW TCP/UDP
Checksum Calculation
IP v4 packets
Yes
Yes
IP v6 packets
(no IP checksum in IPv6)
(no IP checksum in IPv6)
No
No
Packet is an IP fragment
Yes
No
Packet is greater than 1552 bytes; (LPE=1)
Yes
Yes
Packet has 802.3ac tag
Yes
Yes
Packet has IP options
(IP header is longer than 20 bytes)
(IP header is longer than 20 bytes)
Yes
Yes
Packet has TCP or UDP options
Yes
Yes
IP header’s protocol field contains a protocol
other than TCP or UDP.
other than TCP or UDP.
Yes
No