From: Colm O'Leary (Colm.O'Leary@anpost.ie)
Date: Fri Jan 12 2007 - 06:31:14 ART
Anthony,
Thanks for your input. I guess on the day it will be clear, what
exactly will be required. I am just curious if there are any unknown
gotcha's associated with enabling MST. For example, MST 0 which all
unmapped vlans will belong to, should vlan 1 be removed from this
instance and mapped to a defined instance. Again it may be one for the
Proctor, or it may be clearer on the day....
Colm
-----Original Message-----
From: anthony.sequeira@thomson.com [mailto:anthony.sequeira@thomson.com]
Sent: 11 January 2007 17:51
To: Colm O'Leary; ccielab@groupstudy.com
Subject: RE: MST & RSTP
You make some awesome points here about MST - in order to really get it
fine tuned and experience the best in convergence - you should use
PortFast on edge ports where appropriate and you should use Full Duplex
P2P between your switches.
With that said - remember - the Lab Exam is not about best practices. In
fact, the network they have you build can be looked at as a total design
disaster in most cases.
A perfect example is Virtual Links with OSPF - often times the Lab Exam
writer seems to think those are the best things since sliced bread!
While "over configuring" is sometimes no problem to make sure you get
points - in the case you describe I think you are going too far.
If I am asked to configure MST and that is it - I am not going to bother
hunting down all of the ports where PortFast would be appropriate unless
I am explicitly asked to do so.
Remember also that they need to construct an exam that is easily
gradable. That means the grading script is looking for pretty simple
config blocks or for the existence of routes, etc.
I certainly hope this post helps you....
Anthony J. Sequeira
#15626
-----Original Message-----
From: nobody@groupstudy.com [mailto:nobody@groupstudy.com] On Behalf Of
Colm O'Leary
Sent: Thursday, January 11, 2007 7:18 AM
To: ccielab@groupstudy.com
Subject: MST & RSTP
Group,
When you enable MST in a switched environment, by default Rapid
Spanning Tree is implemented. The port roles defined by RSTP [Edge, P2P]
are defined by if portfast is enabled on ports connecting to end
devices or if they are set to full-duplex mode. If in an MST
configuration, you do not explicity configure switchports connected to
end devices in the portfast state, will the stability of the STP
topology be compromised, or will it just increase the STP convergence
time?
The logic to my question is that if you are presented with an MST
configuration in the lab, and you are not explictily asked to configure
the ports either in portfast or in full duplex, should you configure the
interconnects between switches to full duplex and the port connected to
end devices to portfast. I know that the connections between switches
should be set to full-duplex as a matter of best practice, but setting
portfast?
Also if another feature, such as enabling BPDUGUARD globally, which is
directly linked to ports that have portfast enabled, could cause
confusion.
If anyone has any comments on this I would welcome any input.
Regards,
Colm
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