At 07:27 PM 8/28/01, Gareth Hinton wrote:
>Always thought that Diameter was a misleading term.
>If the root bridge is physically in the centre of the bridged network, the
>diameter is actually the radius.
>Hmmm - more coffee - it's late.
Hmm, it is late, but I don't think the placement of the root bridge matters
in this question. The Cisco text says "This means that two distinct bridges
in the network should not be more than seven hops away the one to the
other." The English is awkward, but the meaning is clear and notice that
there's no mention of the root bridge.
IEEE 802.1D says that the recommended value for the maximum bridge diameter
is 7, and its definition is "The maximum bridge diameter of the Bridge LAN:
The maximum number of Bridges between any two points of attachment of end
stations."
Priscilla
>""Leigh Anne Chisholm"" wrote in message
>[EMAIL PROTECTED]">news:[EMAIL PROTECTED]...
> > Here's something funky I've just started researching. Thought many of
you
> > might not be aware of this...
> >
> > Awkward STP Parameter Tuning and Diameter Issues
> >
> > We already saw that an aggressive value for the max-age parameter and the
> > forward-delay could lead to a very unstable STP. The loss of some BPDUs
>can
> > then cause a loop to appear. Another issue, not very known, is related to
> > the diameter of the bridged network. The conservative default values for
>the
> > STP impose a maximum network diameter of seven. This means that two
>distinct
> > bridges in the network should not be more than seven hops away the one to
> > the other. Part of this restriction is coming from the age field BPDU
>carry:
> > when a BPDU is propagated from the root bridge towards the leaves of the
> > tree, the age field is incremented each time it goes though a bridge.
> > Eventually, when the age field of a BPDU goes beyond max age, it is
> > discarded. Typically, this will occur if the root is too far away from
>some
> > bridges of the network. This issue will impact convergence of the
spanning
> > tree.
> >
> >
> > This came from: http://www.cisco.com/warp/public/473/16.html#2f
________________________
Priscilla Oppenheimer
http://www.priscilla.com
Message Posted at:
http://www.groupstudy.com/form/read.php?f=7&i=17752&t=17489
--------------------------------------------------
FAQ, list archives, and subscription info: http://www.groupstudy.com/list/cisco.html
Report misconduct and Nondisclosure violations to [EMAIL PROTECTED]
