I agree with you, token ring is a nice protocol, and I have studied it
at great length. I've also dealt with several very bad implementations
of it, which is kinda where that term comes from. But, I have seen some
great implementations of token ring, and those work beautifully. I've
worked with mainly SynOptics MAU's (which are great manageable devices,
if you have the right software for them). I didn't think about the
unpowered MAUs, which I've only dealt with once or twice. In any case,
"wrapping" or "partitioning" a port generally means to shut it off, and
I could see where you would need this in an unpowered device.
Craig
-----Original Message-----
From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED]]On Behalf Of
Jim Erickson
Sent: Thursday, December 28, 2000 10:55 AM
To: [EMAIL PROTECTED]
Subject: Re: "Token Ring in home lab" questions
"Craig Johnson" <[EMAIL PROTECTED]> wrote in message
[EMAIL PROTECTED]">news:[EMAIL PROTECTED]...
> (There's no concept of a
> crossover cable in Broken Ring....err Token Ring)
You know I've usually found that the folks who call it "broken ring"
really
haven't studied it too well. Its a damn nice protocol, with a heck of a
lot
more functionality than the controlled chaos of Ethernet. Too bad its
bound
to go the way of Betamax (also a superior product to its competitors).
> Wrap is for
> management, you can configure MAUs to only allow certain MAC
addresses,
> and if a mac address is used that isn't int the list, the port will
wrap
> (go inactive).
Since the folks that run the SMC web site seem to have forgotten that
SMC
ever made MAUs, I can't look this up. However, very few MAUs have this
type
of functionality unless they are "smart". Usually, cheap MAUs that are
likely to be in a person's lab (which I am assuming we are talking about
here) are unpowered devices, that have no internal processor or memory,
so
there's no way they could filter any MAC addresses. They just have a
bunch
of electical relays in them that are switched via power delivered via
the
NICs attached to them. In such a case, if you connect two MAUs together,
neither will have power to open the relay on the other one, and the ring
will not pass between them. Thus each MAU has to have some sort of
manual
switch which will set the relay correctly. On IBM MAUs, simply having a
connector plugged into a RI/RO port throws the relay. An educated guess
says
that on SMC the "wrap" button is a manual switch to open/close the
relay.
---JRE---
_________________________________
FAQ, list archives, and subscription info:
http://www.groupstudy.com/list/cisco.html
Report misconduct and Nondisclosure violations to [EMAIL PROTECTED]
_________________________________
FAQ, list archives, and subscription info: http://www.groupstudy.com/list/cisco.html
Report misconduct and Nondisclosure violations to [EMAIL PROTECTED]
