From: Vector <vector@itpsg.com>
To: Sebastiaan <S.Breedveld@ITS.TUDelft.NL>
CC: Angus D Madden <ii@cipete.ekilat.com>, debian-user@lists.debian.org
Subject: Re: COM21 is killing me with ARP
Date: Wed, 13 Jun 2001 16:30:48 -0600 (MDT)
The fact that your provider is using an etire class B address space for
a single broadcast network is what should be making you nervous. In most
network architecture schemes, the ip's are divided into blocks and thus
the amount of broadcasts being received by individual hosts are greatly
reduced. I would want to see more of the dump to actually determine if
this is really a problem. ARP's are used to gain the MAC address of a
system with an IP that is on the same network as you are. With a class B
address space of potentially 65,533 hosts on the same broadcast network
you can expect to see *MANY* ARP requests! Is this AT&T, sounds like
something they would do...
vector
On Wed, 13 Jun 2001, Sebastiaan wrote:
> On Wed, 13 Jun 2001, Angus D Madden wrote:
>
> > On Wed, Jun 13, 2001 at 12:01:23PM +0200, Sebastiaan wrote:
> > > a couple of days ago I installed a COM21 cable modem. Although I can
> > > internet without problems, the modem itself is sending me endless
ARP
> > > requests, while my computer does not answer them. I analysed the
data with
> >
> > I have a COM21 and I have the same problem. You'll notice that the TX
> > light on your NIC will never stop. It never used to be a major
problem
> > with my ne2k-pci NIC (until the NIC got toasted for one reason or
> > another). After that I switched to a 3c905*, which seemed to work
great
> > but would go dead after about 15 minutes (presumably because of the
arp
> > bombardment).
> I hope it did not get toated because of the COM21: I only like fried
> chips. I have no trouble with the interface (MACE, PowerMac) and the
link
> is pretty stable until now.
>
> Thanks for the info,
> Sebastiaan
>
> >
> > My solution was to reset with interface with a cron job every 15
> > minutes. It's a total rat-fsck solution, but it works.
> >
> > >
> > > This makes me nervous. 212.127.*.* is my ISP cable modem network.
What is
> > > this, can I stop it?
> > >
> >
> > I'm not sure it comes from one source. If I tcp dump I see many 'arp
> > who has xxx.xxx.xxx.xxx tell xxx.xxx.xxx.xxx' and the ip addresses
jump
> > around all over the place. Not sure how to stop it.
> >
> > g
> >
> >
>
>
>
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