Re: Etherchannel silent mode

From Website I found:
http://etutorials.org/Networking/Lan+switching+fundamentals/Chapter+4.+Layer+2+Fundamentals/EtherChannel/

Silent/Non-Silent modes are involved with unidirectional link failures. It
is possible for a fiber connection to remain up even if one of its
transceivers has become faulty. Non-Silent mode detects faulty RX/TX
transceivers on a fiber port. PAgP will reset the port for 1.6 seconds to
force the other side to shut down as well. A unidirectional link can cause
black holing of traffic because the return traffic is not received by the RX
transceiver. The detection of unidirectional link by a PAgP is about 3.5 *
30 seconds. On the other hand, UniDirectional Link Detection (UDLD) can
detect the failure less than 50 seconds versus PAgP. UDLD will be discussed
later in Chapter 10, "Implementing and Tuning Spanning Tree." In Silent
mode, PAgP does not look for faulty transceivers. The recommendation is to
leave Silent/Non-Silent modes at their default values because UDLD better
addresses this problem. However, for devices that do not support UDLD,
configure Non-Silent mode. Example 4-19 provides useful information about
the channel that was created.

Chris

On Thu, Aug 19, 2010 at 4:43 AM, Keegan Holley <keegan.holley_at_sungard.com>wrote:

> Ok, I'm a little confused by this. As I was the first (and second) time I
> read it. So apparently pagp operates in a silent mode by default where it
> does not require the far end device to send pagp frames before adding a
> port
> to an etherchannel. That makes sense although a little counterintuitive.
> However, if this is the case what's the difference between the negotiated
> modes and unconditional trunking? Also, in the case of auto mode, I
> thought
> the whole point was for it to be passive and wait for PAgP frames to be
> sent.
>
>
> Blogs and organic groups at http://www.ccie.net
>
> _______________________________________________________________________
> Subscription information may be found at:
> http://www.groupstudy.com/list/CCIELab.html
>
>
>
>
>
>
>
>

-- 
Chris Grammer
Network Architect
Essilor of America
(o) 214-496-4714
(c) 972-400-1661
Blogs and organic groups at http://www.ccie.net