Re: arpresolve

[Hakan Olsson <ho@crt.se>]

Well, it's an indication you have a misconfigured network.

You said it yourself; "when the box receives an arp request / reply for a
machine not on one if it's subnets".

That's fairly clear, I think. The other machine should not be present on
this network, i.e a misconfigured network. (I could mention some RFCs
here... :)

Typically, one has mistakenly connected two different networks together in
a hub or a switch, i.e connected the networks on the datalink level. The
internet will work well otherwise, but you'll get bad effects such as
this.

One way to find where it's wrong is to tcpdump the network, listening for
ARPs. With some luck, you'll spot the offender(s).

Finally, I don't really see a point for having, say, a sysctl to disable
legitimate warnings such as these. Convince me otherwise and it might
happen. :)

(If you _really_ want to disable the message, well, the way to go
 currently is to edit the file /usr/src/sys/netinet/if_ether.c, and
 remove/comment out the line printing the message, it should be ca line
 341. After which you rebuild and install the new kernel. I don't
 recommend doing this though.)

/H

On Wed, 6 Jun 2001, the p0pe wrote:

> I know this has been covered before, but in such sporadic detail it hurts.
> Quite often (sometimes as many times as 10-15 a second) i get
> 'arpresolve: can't allocate llinfo'
> the machine(s) i get this on are firewall / NAT / IPsec gateways which see
> quite a bit of traffic. Now from various other posts, i've learned that
> this comes up when the box receives an arp request / reply for a machine
> not on one of it's subnets. and that on freebsd, you can turn off the
> warnings with a sysctl. I played around with sysctl -a for a bit and saw
> no similar sysctls.
> Anyway, any pointers (such as what's causing this if i'm wrong, or ans
> helpfull sysctl's i could play with) would be appreciated.
> +-(:-)
>
>

--
Håkan Olsson <ho@crt.se>        (+46) 708 437 337     Carlstedt Research
Unix, Networking, Security      (+46) 31 701 4264        & Technology AB