[546] in resnet
Re: Wireless vs. Multicast vs. AppleTalk
daemon@ATHENA.MIT.EDU (Joshua Wright)
Fri Dec 7 20:12:05 2001
MIME-Version: 1.0
Content-Type: text/plain
Message-ID: <415D42EC88D4D411A128009027AF978C03A5ECF2@gaspee.jwu.edu>
Date: Fri, 7 Dec 2001 20:05:22 -0500
Reply-To: Resnet Forum <RESNET-L@listserv.nd.edu>
From: Joshua Wright <Joshua.Wright@JWU.EDU>
To: RESNET-L@listserv.nd.edu
Greg,
Can you block by layer 3 address? You could block the multicast address for
Ghost, and let other multicast address traverse onto the wireless LAN.
My 2 cents.
-Joshua Wright
Team Leader, Networks and Systems
Johnson & Wales University
Joshua.Wright@jwu.edu
pgpkey: http://pgp.mit.edu:11371/pks/lookup?op=get&search=0xD44B4A73
fingerprint: FDA5 12FC F391 3740 E0AE BDB6 8FE2 FC0A D44B 4A73
-----Original Message-----
From: Greg Chalfin [mailto:gregc@STANFORD.EDU]
Sent: Friday, December 07, 2001 6:18 PM
To: RESNET-L@listserv.nd.edu
Subject: Wireless vs. Multicast vs. AppleTalk
We've run into some annoying problems in our initial tests of
wireless LAN access in Stanford Libraries. We're trying to use
low-cost access points such as Apple AirPort or Netgear ME102.
We also make a lot of use of the application "Ghost" on the
wired network. It turns out that when a Ghost session (which
is necessarily a multicast session) is running on a subnet,
all Apple or Netgear access points on that subnet become
useless. All of our subnets are switched, using Cisco 1924's
and 2924's which were installed several years ago and do not support
IGMP snooping nor CGMP. A quick-and-dirty fix is to configure the
switches to block multicast packets from being sent to the particular
ports that have access points plugged into them. This solves the
wireless vs. Ghost problem (since all the machines that need the
Ghost session are on the wired network), but it also blocks AppleTalk
from working on Apple laptops when they're connected via wireless,
since AppleTalk uses multicasting to do address resolution and
resource discovery.
I'm hoping someone has seen some of these issues before and knows
a solution.
--
Greg Chalfin
Stanford Libraries
gregc@stanford.edu
___________________________________________________
You are subscribed to the ResNet-L mailing list.
To subscribe, unsubscribe or search the archives,
go to http://LISTSERV.ND.EDU/archives/resnet-l.html
___________________________________________________
___________________________________________________
You are subscribed to the ResNet-L mailing list.
To subscribe, unsubscribe or search the archives,
go to http://LISTSERV.ND.EDU/archives/resnet-l.html
___________________________________________________
