ifconfig fxp0 link0 from rc.conf?

[Erik Trulsson]

On Sat, Feb 02, 2008 at 07:42:46PM +0000, Matthew Herzog wrote:
> What is the proper way to turn on the checksum offloading for an Intel
> fxp card?
> 
> Yes, it's obvious I can do it by hand with ifconfig. That works fine.
> How do enable it in rc.conf so that
> it happens upon each reboot? I searched the www for an hour and found no
> examples.
> 
> My guess would be -flags link0 but I'd rather be sure before hosing the
> interface on this physically remote machine ;)
> 


The 'link0' part is for enabling interrupt moderation. That can be enabled
with a line in /etc/rc.conf similar to
 ifconfig_fxp0="inet 10.1.5.1 netmask 255.255.255.0 link0"
(Adjust IP-address and netmask as needed.)


Checksum offloading should be enabled automatically for those cards which
support it.  Most chips supported by fxp(4) do not have support checksum
offloading. (The i82557, i82558, and i82559 do not support checksum
offloading.  The i82550 does support it.  Newer chips probably also support
it.)

To enable recieve/transmit checksum offloading just add 'rxcsum'/'txcsum'
respectively to the ifconfig line, but as I said this is normally enabled
automatically for all NICs that have working support for it.
(Use '-rxcsum' and '-txcsum' to disable them if they are enabled and you
do not want to use checksum offloading.)

You can run "ifconfig -m fxp0" to see what the card supports.
The 'options' line in the output is those that are enabled while the
'capabilities' line are those which are supported.
Checksum offloading is indicated by RXCSUM and TXCSUM (for receive and
transmit respectively.)





-- 
<Insert your favourite quote here.>
Erik Trulsson
ertr1013 at student.uu.se