dhclient and wpa_supplicant

David Wolfskill david at catwhisker.org
Mon Aug 1 15:35:03 GMT 2005

On Mon, Aug 01, 2005 at 11:21:56AM -0400, James Snow wrote:
> On Fri, Jul 29, 2005 at 06:08:53PM -0700, Sam Leffler wrote:
> > 
> > So the question is what are the outstanding issues with dhclient and 
> > wpa_supplicant?  I'm mostly concerned with wireless devices but feel 
> > free to talk about wired interfaces too.  
> My biggest outstanding complaint is when booting with a wired network
> and no present wireless network, if dhclient has any recorded leases for
> the wireless interface, it will attempt to use the most recent one and
> blows away the default gateway for the wired network. I then have to manually
> 'netif stop ath0' and 'netif restart em0.'
> Not sure what the best solution is....

For reasons that aren't relevant to this discussion, I am not running
the code in question.

However, when I got my current laptop, it forced me to re-think how I
handle connectivity:  thitherto, I had placed whatever type of NIC I
wanted in a PCMCIA slot; FreeBSD saw the new device, andthat was

The current laptop has both wired and wireless NICs built in; short of
surgery on the machine, each will always appear available.  And there
are times when I do not want to use the wireless NIC, even if I'm in
range of an AP with which I could associate:  here at home, for example,
my APs are on a "guest" network that I don't trust very much, so if I
want to use certain services, I'll use the "trused" wired net.

I adopted an approach (encoded in a Perl script I cobbled up) of
enumerating a set of regexen for wireless NICs -- all others are treated
as "wired."  I then check to see if there's a "link" condition on any
wired NIC; if there is, I use that NIC preferentially.

It's only if there's no link on a wired NIC taht I try to use a wireless

The rationale is that connecting a wire to a wired NIC is something that
requires a bit more than merely accidental proximity; I assume(!) that I
only plug the wire in if I want to use the NIC.

I don't know if this idea is useful for others or if it's usable at all
for the situation in question; I offer it as an approach that works
pretty well for me.

(The above-cited Perl script also, for wireless NICs, invokes another
Perl script to handle acquiring a link -- dealing with SSIDs, WEP,
whatever -- and then for either kind of NIC will invoke dhclient.)

David H. Wolfskill				david at catwhisker.org
Any given sequence of letters is a misspelling of a great many English words.

See http://www.catwhisker.org/~david/publickey.gpg for public key.

More information about the freebsd-current mailing list