[c-nsp] Fast UDLD timers in SXI?

[David Hughes]

Hi

Good point.  I see CFM has been introduced in SXI.  But after wading  
through the doco, particularly in the area of "Continuity Check  
Messages" I see ....

-----
CFM CCMs have the following characteristics:

•Transmitted at a configurable periodic interval by MEPs. The interval  
can be from 10 seconds to 65535 seconds, the default is 30.

•Contain a configurable hold-time value to indicate to the receiver  
the validity of the message. The default is 2.5 times the transmit  
interval.

-----


So I see we now have yet another protocol implementation that isn't  
going to help us improve the availability of the networks we run.  10  
second hello timers?  That's soooo 1980's.  :-)

According to feature navigator, the "UDLD Enhancements" feature which  
I believe provides fast timers is available in SXH4 and SXI.  Our  
boxes are SXF and SXH3.  Can someone with an SXI box check the  
configuration range for

	(config)#udld message time ?
         <7-90> Time in seconds between sending of messages in steady  
state


Thanks

David
...



On 05/02/2009, at 12:47 AM, Mauritz Lewies wrote:

> I've not had much chance to play with it but will Ethernet CFM not  
> work
> for this?
>
>
>
>
>
> On Wed, 2009-02-04 at 08:49 +1000, David Hughes wrote:
>
>> Yup, that's exactly the situation.  STP will work around some of the
>> problem caused by this but if you are presenting an etherchannel over
>> multiple xconnects you can't pick up the link failure of part of the
>> etherchannel without UDLD.  We did some initial proof of concepts  
>> with
>> 2900s running 2 second timers and it was great.  Imagine the look on
>> my face when we found out that 6500s don't have the functionality  
>> of a
>> $1,000 access switch .....
>>
>> So, is the config option on SXI still 7 seconds at best?
>>
>>
>> Thanks
>>
>> David
>> ...
>>
>>
>> On 03/02/2009, at 7:45 PM, Thomas Dupas wrote:
>>
>>> I assume it's a L2 link (EoMPLS), so BFD won't help much.
>>>
>>> We're in the same situation, also stuck with UDLD timers and 2
>>> parallel EoMPLS xconnects. I can't get the convergence lower then 20
>>> seconds with the default UDLD, so I'm also hoping for fast UDLD
>>>
>>> Best Regards,
>>>
>>> Thomas
>>>
>>> ________________________________________
>>> Van: cisco-nsp-bounces at puck.nether.net [cisco-nsp-bounces at puck.nether.net
>>> ] namens Gert Doering [gert at greenie.muc.de]
>>> Verzonden: dinsdag 3 februari 2009 8:15
>>> Aan: David Hughes
>>> CC: Cisco NSP ((E-mail))'
>>> Onderwerp: Re: [c-nsp] Fast UDLD timers in SXI?
>>>
>>> Hi,
>>>
>>> On Tue, Feb 03, 2009 at 04:30:50PM +1000, David Hughes wrote:
>>>> Can someone verify if 12.2(33)SXI offers fast UDLD timers (i.e.  
>>>> down
>>>> to 1 second) or if we are still stuck with the old 7 sec timers.   
>>>> We
>>>> can do 1 sec UDLD on 2900 class switches so I hope we see it in the
>>>> "premier switching platform" some time soon.  We need some way to
>>>> pick
>>>> up a link failure at the far end of an EoMPLS xconnect in a
>>>> reasonable
>>>> time.
>>>
>>> Can you use BFD?
>>>
>>> (Yes, this is not answering your question - I don't know the answer
>>> - but
>>> it might be an alternative approach if this a layer 3 link)
>>>
>>> gert
>>> --
>>> USENET is *not* the non-clickable part of WWW!
>>>                                                          //www.muc.de/~gert/
>>> Gert Doering - Munich, Germany                             gert at greenie.muc.de
>>> fax: +49-89-35655025                        gert at net.informatik.tu-muenchen.de
>>
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