Seeing "rn_addmask: mask impossibly already in tree" on console

[David Wolfskill]

Running:

FreeBSD g1-227.catwhisker.org 9.1-PRERELEASE FreeBSD 9.1-PRERELEASE #273 241679M: Thu Oct 18 04:52:24 PDT 2012     root at g1-227.catwhisker.org:/usr/obj/usr/src/sys/CANARY  i386

on my laptop, at times when I switch from X to vty0, I see (e.g.):

Oct 18 08:27:07 g1-227 kernel: rn_addmask: mask impossibly already in treern_addmask: mask impossibly already in treern_addmask: mask impossibly already in treern_addmask: mask impossibly already in treern_addmask: mask impossibly already in treern_addmask: mask impossibly already in treern_addmask: mask impossibly already in tree...


I see where the message is issued (sys/net/radix.c:539 @r210122,
last updated 2010-07-15 14:41:59Z).

As this is a laptop, and thus subject to being connected to networks
I do not control, I run a packet filter on it, and the one with
which I happen to be most familair is ipfw.  Thus that's what I
use.

So it's possible that either ipfw or routing is driving rn_addmask().

However, I'm unclear on:

* What (specifically) is actually causing this.

* Whether or not it's enough of an issue or problem that I should take
  evasive action.  Put differently: what is my exposure here?

* If so, what sort of evasive action is appropriate for me to take.

I suppose I could try a packet-capture, but the lack of timestamps
make correlating the message-issuance with particular packets a
little more challenging than I'd prefer.

I note, too, that I'm running a very similar ipfw configuration on
the packet-filter machine here at home; while I find the above-
quoted whines in /var/log/console.log on the laptop, I do not find
them mentioned in that file for the packet filter machine.

Clues?

[Please include me in the recipient list, as I'm not subscribed to net@;
I've set Reply-To as a hint.]

Thanks!

Peace,
david
-- 
David H. Wolfskill				david at catwhisker.org
Taliban: Evil men with guns afraid of truth from a 14-year old girl.

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