Re: ARP flooded

From: Ron! (anemail_at_spam.net)
Date: 09/28/05 

Date: Wed, 28 Sep 2005 07:56:20 GMT

"TaranFX" <taranfx@gmail.com> wrote in message
news:1127893312.178941.184320@f14g2000cwb.googlegroups.com...
> my network is under discreet attacks with ARP packets. bcoz of this my
> switch mac address table is flooding, i tried increasing table size but
> of no use.
> Bcoz of this my network has gone slow, there are many packet drops,
> data transfer are less than half wat it used to be earlier.

you're kidding right? this attack is so old i can't imagine you've been
reading this newsgroup prior to this post. a simple network
snoop|tcpdump|ethereal or whatever will show the packets, give you the
source ip, and then simply find the offending process on the
server(s)/workstation(s) in question (it's probably multiple servers or
workstations, 99% guaranteed their windows based which is obvious from your
post) and shut it off/disconnect it from the network. since you know it's an
arp flood, use the same tool you used to deduce this in the first place to
see where the traffic originates.

> How can i prevent ARP attack?

this is difficult, because arp traffic is normal. if you're truly having an
arp flood, you've already answered your own question, unless you don't what
you're talking about...

> How do they burst so much ARP?

continually sending arp requests; easy to spot as a lot of times poor coding
will show these as arp requests to consecutively numbered ip addresses on
your net/subnet...

> can anybody gimme a source code of ARP flooder so that i can study it and
prevent it from happening.

google the rfc for arp, it will give more information than you can decipher
or apparently understand... i'm not trying to be an ***, i just play one
on usenet...

Ron!

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