On 5/24/07, Erik Trulsson <[EMAIL PROTECTED]> wrote:
Checksum offloading is usually enabled by default for hardware that supports it (assuming that the driver for that hardware also supports it of course.) To see if a particular interface uses checksum offloading you can look at the output of 'ifconfig -m'. The "options" line in the output refers to those features that are enabled, while the "capabilities" line refers to those features that are available. (Checksum offloading for receive and transmit show up as RXCSUM and TXCSUM respectively.) Ifconfig can also be used to enable/disable the offloading - see the ifconfig(8) manpage for details and syntax. It can sometimes be desirable to turn of checksum offloading if one suspects that the hardware has some bugs in it that can cause the checksum to be wrong. (For those cases were the hardware has known bugs in this area, the driver normally disable checksum offloading by default.) Most hardware supported by the fxp(4) driver do not have support for checksum offloading, but some do. (The fairly commonly used 82559 chip does not support checksum while the less common 82550 chip does, for example.)
Thanks for the info. This is cool. My Intel NIC is the 82550. That explains a few things. Thanks again for the info on how these are used FreeBSD. Andy _______________________________________________ email@example.com mailing list http://lists.freebsd.org/mailman/listinfo/freebsd-questions To unsubscribe, send any mail to "[EMAIL PROTECTED]"