Re: Cisco switch

From: Bryan Bassett (bbassett)
Date: 02/14/05 

Date: Mon, 14 Feb 2005 15:36:32 -0500

The Cisco 2950 is a very 'smart' switch and has a few features that,
when enabled, will cause it to not enable a port for 40 seconds or so.
Below is a link from Cisco about it along with a snippet.
In my experience, disabling STP (enabling PortFast) and Trunking on
internal ports will allow them to be enabled nearly immediately.

Bryan

http://www.cisco.com/en/US/products/hw/switches/ps700/products_tech_note09186a00800b1500.shtml

-------------------
With the various features that are now included in some switches, it can
take close to a minute for a switch to begin servicing a newly connected
workstation. This delay would affect the workstation every time it is
turned on or rebooted. The four main features that cause this delay are
as follows:

  - Spanning Tree Protocol (STP)
  - EtherChannel negotiation
  - Trunking negotiation
  - Link speed/duplex negotiation between the switch and the workstation

The four features above are listed in order of causing the most delay
(STP) to causing the least delay (speed/duplex negotiation). A
workstation connected to a switch usually does not cause Spanning Tree
loops, usually does not need EtherChannel, and usually does not need to
negotiate a trunking method. Disabling link speed/detection negotiation
can also reduce port delay if you need to optimize your startup time as
much as possible.
-------------------

Mo wrote:
> Hi john,
> thanks for replying
> did u have these CAPS (30pF on XTAL1,XTAL2) on before?
> if so, what values where u using?
> we are using 18pF CAPS , its oscilatting at 25.00 mHZ.
>
> i understood from ur reply that changing the CAPS solved ur problem
> directly.
> was there any accompanying Software changes?
> here is my email
>
> marabo82@hotmail.com
> thanks again
>
> Mo
>

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