how to attach class C net to an interface?

[Matthew Seaman]

On Fri, Jun 04, 2004 at 11:36:10AM +0400, Artem Koutchine wrote:

> > for (( foo = 1; foo < 255; foo++ )); \
> > do ifconfig fxp1 alias 172.16.100.$foo netmask 0xffffffff; \
> > done

> Thank you for the scrip. I will then asign a single main ip to the interface
> in rc.conf and then run this script from /usr/local/etc/rc.d because i think
> rc.local is merged after each cvp/buildworld/installworld/mergmaster,
> so /usr/local/etc/rc.d is a safer place to to keep it. Right or not?

Probably the best place to put this is in a file named 'start_if.fxp1'
assuming fxp1 is the interface you want all this to happen to.  That
will be read into /etc/rc.network and executed by this bit of code:

        for ifn in ${network_interfaces}; do
                if [ -r /etc/start_if.${ifn} ]; then
                        . /etc/start_if.${ifn}
                        eval showstat_$ifn=1
                fi

This effectively lets you introduce custom bits of shell script into
the standard /etc/rc.network script without having to worry about
keeping that script patched and in synch across system updates.

There isn't a similar 'stop_if.fxp1' facility -- just disabling the
interface usually does the trick.
 
> The other question, will assigning 200+ ip addresses  degrade tcp/ip
> perfomance noticeably? 

Hard to say.  Probably not a huge amount, but it will depend on your
hardware amongst other things.  The only way to know for sure is to
run some tests yourself.  

> How to i spell noticably or noticaebly?  :)

noticeably

	Cheers,

	Matthew

-- 
Dr Matthew J Seaman MA, D.Phil.                       26 The Paddocks
                                                      Savill Way
PGP: http://www.infracaninophile.co.uk/pgpkey         Marlow
Tel: +44 1628 476614                                  Bucks., SL7 1TH UK
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