Date: Sun, 26 Nov 2000 12:31:53 -0800 From: "Crist J . Clark" <cjclark@reflexnet.net> To: Dominick LaTrappe <seraf@2600.COM> Cc: freebsd-security@FreeBSD.ORG Subject: Re: static ARP tables Message-ID: <20001126123153.D70192@149.211.6.64.reflexcom.com> In-Reply-To: <Pine.NEB.4.21.0011261501020.15375-100000@phalse.2600.com>; from seraf@2600.COM on Sun, Nov 26, 2000 at 03:10:16PM -0500 References: <200011252212.PAA26585@faith.cs.utah.edu> <Pine.NEB.4.21.0011261501020.15375-100000@phalse.2600.com>
next in thread | previous in thread | raw e-mail | index | archive | help
On Sun, Nov 26, 2000 at 03:10:16PM -0500, Dominick LaTrappe wrote:
> On Sat, 25 Nov 2000 "David G. Andersen" <dga@pobox.com> wrote:
> > When used in conjunction with switch-enfored MAC security, it's actually
> > quite useful. You yourself state this; I have a need for exactly this
> > kind of functionality for Utah's network testbed, actually.
>
> What I'd really like to see is a 'static' flag that can be added to
> individual ARP table entries. I have several networks with servers and
> routers whose MAC/IP/switchport associtions should never change, but also
> workstations that change all the time.
>
> I'm going to try to work on a patch for this, though maybe someone already
> knows a hack?
$ man arp
.
.
.
-s hostname ether_addr
Create an ARP entry for the host called hostname with the Ether-
net address ether_addr. The Ethernet address is given as six hex
bytes separated by colons. The entry will be permanent unless
the word temp is given in the command. ^^^^^^^^^
Writing a script to 'permanentize' an existing entry is
straightforward,
#!/bin/sh
#
# arpperm
#
# Usage: arpperm hostname | ip
ARP=/usr/sbin/arp
if [ -z $1 ] || [ $# -gt 1 ]; then
echo "Usage: $0 hostname | ip" >&2
exit 1
fi
MAC=`$ARP -n $1 | cut -f4 -d" "`
if expr $MAC : '[0-9a-f]*:[0-9a-f]*:[0-9a-f]*:[0-9a-f]*:[0-9a-f]*:[0-9a-f]*' > /dev/null 2>&1; then
$ARP -S $1 $MAC
else
echo "$0: trouble getting MAC address" >&2
exit 1
fi
exit 0
--
Crist J. Clark cjclark@alum.mit.edu
To Unsubscribe: send mail to majordomo@FreeBSD.org
with "unsubscribe freebsd-security" in the body of the message
Want to link to this message? Use this URL: <https://mail-archive.FreeBSD.org/cgi/mid.cgi?20001126123153.D70192>