Re: IERS Lab4 Task1.3 - Loopguard and UDLD

Nadeem

When configured as

(config)# udld {enable|aggressive)
only affects fiber ports

(config-if)# udld port aggressive
can be used on fiber ports or copper links.

The aggressive option forces the link to shut down when a unidirectional
link is detected. So why worry about using loopguard?

Thanks

-Mike

On Sun, Jan 24, 2010 at 8:49 AM, Nadeem Rafi <nrafia_at_gmail.com> wrote:

> What i know, UDLD is basically developed for Fiber optics, where chance of
> one way communication are more than any thing else. And UDLD uses its own
> mechanism to detected unidirectional links.
>
> Where as LoopGuard uses STP mechanism to detect unidirectional links and
> mostly enabled for copper links.
>
> HTH
>
> On Sun, Jan 24, 2010 at 3:05 PM, Michael McFarlin <router.genie_at_gmail.com>wrote:
>
>> Experts,
>>
>> I have a question about UDLD and Loopguard in one of the IERS labs. I
>> don't
>> think that loopguard is needed at all here. Why would you have to worry
>> about SW1 making the Fa0/15 a designated port if UDLD has already taken
>> the
>> port down? By default UDLD acts faster than Loopguard by default right?
>>
>>
>> Task
>>
>> Administrators of your network are concerned about SW1 and SW2 not
>> being able to detect a link failure on port Fa0/15.
>>
>> Configure SW1 and SW2 so that port Fa0/15 is brought down in the case
>> that either switch can send traffic, but not receive, or vice versa.
>>
>> As an additional precaution, configure SW1 so that interface Fa0/15 is
>> not
>> mistakenly elected as a designated port in the above case.
>>
>> Answer
>>
>> SW1:
>> interface FastEthernet0/15
>> udld port aggressive
>> spanning-tree guard loop
>> SW2:
>> interface FastEthernet0/15
>> udld port aggressive
>>
>>
>> -Mike
>>
>>
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>

-- 
Mike McFarlin
router.genie_at_gmail.com
Blogs and organic groups at http://www.ccie.net