From: dwhitley@xxxxxxxxx
Date: Tue Apr 09 2002 - 10:33:49 GMT-3
Austin,
I agree with your thinking. The point you raise has always bothered me
concerning this question, there is only one switch. So disabling spanning
tree seems to be the only option. The "trick" to this question is people
trying to solve it with the priority or mac address.
Dean
-----Original Message-----
From: austin.2.alao@bt.com [mailto:austin.2.alao@bt.com]
Sent: Tuesday, April 09, 2002 8:13 AM
To: tobrien@cinci.rr.com; clarson52@comcast.net; sandyccie@yahoo.com;
gparrish@yahoo.com; mamoor@ieee.org
Cc: tsabry@slb.com; jgraun@attbi.com; bsin@erols.com; whitfill@cox.net;
ccielab@groupstudy.com
Subject: RE: Lab Tomorrow! Need Help
Dear Tim,
Doesn't your point kind of contradict itself?
If the lab is not real life, and you are only supposed to configure things
as they exist, surely with only One Ethernet switch, setting the priority to
the highest means it can never become root for that vlan.
Since when did they start adding switches to the lab after you finished?
Do you get my point here?
Ok, now for the serious stuff, a switch CAN become root even with the
highest priority set.
So if the question said "UNDER NO CIRCUMSTANCE" they that does not meet the
requirement.
The question is basically asking you to create a "SINGLE switch" L2 LAN
where NO root will be required.
Disable STP is the ONLY way to achieve this under ALL circumstances cos the
switch will never see any other switches.
My $0.2
Austin.
-----Original Message-----
From: Tim O'Brien [mailto:tobrien@cinci.rr.com]
Sent: 09 April 2002 09:33
To: Chris Larson; Sandro Ciffali; Greg Parrish; Ahmed Mamoor Amimi
Cc: tsabry; 'Jason'; 'Bob Sinclair'; 'Larry Whitfill'; ccielab
Subject: RE: Lab Tomorrow! Need Help
Again... you are overthinking it. If the question states that you need to
set something for a particular vlan, set it for that vlan.. What happens on
other vlans DOES NOT MATTER! You are there to configure what is asked in the
question. If you do not, you will not pass....
Tim
CCIE 9015
-----Original Message-----
From: Chris Larson [mailto:clarson52@comcast.net]
Sent: Monday, April 08, 2002 10:20 PM
To: Sandro Ciffali; Greg Parrish; Ahmed Mamoor Amimi
Cc: Tim O'Brien; tsabry@slb.com; 'Jason'; 'Bob Sinclair'; 'Larry Whitfill';
ccielab@groupstudy.com
Subject: Re: Lab Tomorrow! Need Help
If you only disable spanning tree for a particular vlan then wouldn't it
still be possible for the switch to become root for another vlan, assuming
you are doing PVST? If you are running PVST then you would have to set the
priority high on all the vlans so it wouldn't become the root on any, or
disable spanning on all of them, definetly not a good idea. If you are not
running PVST, then why not just change the priority.
----- Original Message -----
From: "Sandro Ciffali" <sandyccie@yahoo.com>
To: "Greg Parrish" <gparrish@yahoo.com>; "Ahmed Mamoor Amimi"
<mamoor@ieee.org>
Cc: "Tim O'Brien" <tobrien@cinci.rr.com>; <tsabry@slb.com>; "'Jason'"
<jgraun@attbi.com>; "'Bob Sinclair'" <bsin@erols.com>; "'Larry Whitfill'"
<whitfill@cox.net>; <ccielab@groupstudy.com>
Sent: Monday, April 08, 2002 8:15 PM
Subject: Re: Lab Tomorrow! Need Help
> My vote goes for Tim,
> I would read the question carefuly, If the lab says
> the switch should never become root, the only answer
> is to disable the spantree for that vlan, Yes there
> are drawbacks doing that, But remember you are not
> turning off spanning tree for the switch, you are
> turning off for that vlan. IF the question says make
> the switch less probable to be root then i would
> increase the priority. Making the priority 0 is
> definatly making it the root, I have tried this using
> a switch and a router as a bridge with spanning tree.
>
> Sandeep
> 8988
> --- Greg Parrish <gparrish@yahoo.com> wrote:
> > I think turning it off all together is the wrong
> > answer. Just like in OSPF if
> > they say never become the DR, they dont mean to turn
> > off OSPF, just set the
> > priority to 0. They need to rephrase the question
> > because as someone said I can
> > always change all the other switches on the lan to
> > the same priority and you
> > will become root if you now have the lowest mac, so
> > again no guarantee you wont
> > be root which is what they are asking you for and
> > thus leaves the question
> > open.
> >
> > Greg
> >
> >
> >
> >
> > Ahmed Mamoor Amimi wrote:
> >
> > > good one..... <grin>
> > >
> > > -Mamoor
> > >
> > > ----- Original Message -----
> > > From: Tim O'Brien <tobrien@cinci.rr.com>
> > > To: <tsabry@slb.com>; 'Jason' <jgraun@attbi.com>;
> > 'Bob Sinclair'
> > > <bsin@erols.com>; 'Larry Whitfill'
> > <whitfill@cox.net>
> > > Cc: <ccielab@groupstudy.com>
> > > Sent: Monday, April 08, 2002 7:22 AM
> > > Subject: Re: Lab Tomorrow! Need Help
> > >
> > > > Sure, it definitely has drawbacks, but remember
> > that the lab is not real
> > > > life.. you are there to "meet the requirements".
> > Don't overthink things,
> > > > just do what is asked...
> > > >
> > > > Tim
> > > > CCIE 9015
> > > >
> > > > ----- Original Message -----
> > > > From: "Tarek Sabry" <tsabry@houston.sns.slb.com>
> > > > To: "'Tim O'Brien'" <tobrien@cinci.rr.com>;
> > "'Jason'" <jgraun@attbi.com>;
> > > > "'Bob Sinclair'" <bsin@erols.com>; "'Larry
> > Whitfill'" <whitfill@cox.net>
> > > > Cc: <ccielab@groupstudy.com>
> > > > Sent: Sunday, April 07, 2002 9:54 PM
> > > > Subject: RE: Lab Tomorrow! Need Help
> > > >
> > > >
> > > > Tim
> > > >
> > > > But doesn't turning it off has its own
> > drawbacks???
> > > >
> > > > Tarek
> > > >
> > > > -----Original Message-----
> > > > From: nobody@groupstudy.com
> > [mailto:nobody@groupstudy.com]On Behalf Of
> > > > Tim O'Brien
> > > > Sent: Sunday, April 07, 2002 8:27 PM
> > > > To: Jason; 'Bob Sinclair'; 'Larry Whitfill'
> > > > Cc: ccielab@groupstudy.com
> > > > Subject: RE: Lab Tomorrow! Need Help
> > > >
> > > >
> > > > A Priority of 0 is considered better (higher
> > priority) than 1 and will
> > > most
> > > > likely take over root priority...
> > > >
> > > > To give a switch the "worst" possible chance of
> > becoming root, set
> > > priority
> > > > to 65535 for that vlan...
> > > >
> > > > To "ensure" that the switch "never" becomes
> > root, turn off spanning tree
> > > for
> > > > that vlan....
> > > >
> > > > Just my thoughts..
> > > >
> > > > Tim
> > > > CCIE 9015
> > > >
> > > >
> > > > -----Original Message-----
> > > > From: nobody@groupstudy.com
> > [mailto:nobody@groupstudy.com]On Behalf Of
> > > > Jason
> > > > Sent: Sunday, April 07, 2002 7:53 PM
> > > > To: 'Bob Sinclair'; 'Larry Whitfill'
> > > > Cc: ccielab@groupstudy.com
> > > > Subject: RE: Lab Tomorrow! Need Help
> > > >
> > > >
> > > > That might work but if another switch gets added
> > to the STP domain and
> > > > your switch has a lower mac-address then it will
> > become the root bridge
> > > > assuming that the priority is 65535. I thought
> > I read somewhere that
> > > > using 0 will make sure that it will never become
> > a root bridge.
> > > >
> > > > Jason
> > > >
> > > > -----Original Message-----
> > > > From: nobody@groupstudy.com
> > [mailto:nobody@groupstudy.com] On Behalf Of
> > > > Bob Sinclair
> > > > Sent: Sunday, April 07, 2002 5:04 PM
> > > > To: Larry Whitfill
> > > > Cc: ccielab@groupstudy.com
> > > > Subject: Re: Lab Tomorrow! Need Help
> > > >
> > > > Larry,
> > > >
> > > > I would suggest making the bridge priority
> > 65535, the highest possible
> > > > value.
> > > >
> > > > Good luck!
> > > >
> > > > -Bob
> > > >
> > > > ----- Original Message -----
> > > > From: "Larry Whitfill" <whitfill@cox.net>
> > > > To: <ccielab@groupstudy.com>
> > > > Sent: Sunday, April 07, 2002 5:43 PM
> > > > Subject: Lab Tomorrow! Need Help
> > > >
> > > >
> > > > > Hello fellow CCIE waqnnabes and accomplished
> > CCIEs!
> > > > >
> > > > > I'm sittingin my hotel 13 hours from ground
> > zero and needed some
> > > > > clarification and help.
> > > > >
> > > > > 1. When one wants to ensure that his switch
> > does not become root under
> > > > any
> > > > > circumstance does he set the bridge priority
> > to 0, does he set the
> > > > priority
> > > > > to the highest possible value, or does he do
> > someting entirely
> > > > different.
> > > > > This has been kicked around quite a bit, but I
> > never found a
> > > > difinitive
> > > > > answer here or on CCO, books, etc., and don't
> > have two CATs to test.
> > > > >
> > > > > 2. When using DLSW+ peer-on-demand, do I also
> > have to configure a
> > > > border
> > > > > peer, use the promiscuous keyword, both or
> > neither?
> > > > >
> > > > > Thanks in advance!
> > > > >
> > > > > Larry
> > > > >
> >
This archive was generated by hypermail 2.1.4 : Thu Jun 13 2002 - 10:58:00 GMT-3