freebsd documentation

[Bill Moran]

Adam Newhard wrote:
> the document page listed at 
 > http://www4.us.freebsd.org/doc/en_US.ISO8859-1/books/handbook/configtuning-virtual-hosts.html
> 
> at the bottom, i'm pretty sure you guys have an error in your page (it's
 > something anyone who doesn't have a clue would pick out though, so it's not
 > a big deal).  From the page:
> *******************************
> 
> For example, consider the case where the fxp0 interface is connected to two
 > networks, the 10.1.1.0 network with a netmask of 255.255.255.0 and the
 > 202.0.75.16 network with a netmask of 255.255.255.240. We want the system to
 > appear at 10.1.1.1 through 10.1.1.5 and at 202.0.75.17 through 202.0.75.20.
> 
> The following entries configure the adapter correctly for this arrangement:
> 
>  ifconfig_fxp0="inet 10.1.1.1 netmask 255.255.255.0"
>  ifconfig_fxp0_alias0="inet 10.1.1.2 netmask 255.255.255.255"
>  ifconfig_fxp0_alias1="inet 10.1.1.3 netmask 255.255.255.255"
>  ifconfig_fxp0_alias2="inet 10.1.1.4 netmask 255.255.255.255"
>  ifconfig_fxp0_alias3="inet 10.1.1.5 netmask 255.255.255.255"
>  ifconfig_fxp0_alias4="inet 202.0.75.17 netmask 255.255.255.240"
>  ifconfig_fxp0_alias5="inet 202.0.75.18 netmask 255.255.255.255"
>  ifconfig_fxp0_alias6="inet 202.0.75.19 netmask 255.255.255.255"
>  ifconfig_fxp0_alias7="inet 202.0.75.20 netmask 255.255.255.255"
> If you're configuring your system how you said above, those last 3 lines
 > needs a netmask of 255.255.255.240, not .255

No.  Read this paragraph from that page:

"The calculation of alias netmasks is important, but fortunately quite simple.
  For a given interface, there must be one address which correctly represents
  the network's netmask. Any other addresses which fall within this network must
  have a netmask of all 1s."

The example is correct, and the page _does_ explain why.

-- 
Bill Moran
Potential Technologies
http://www.potentialtech.com