From: Scott M Vermillion (scott_ccie_list@it-ag.com)
Date: Thu Nov 13 2008 - 00:14:43 ARST
The devil is often times in the details. Last year I was hired to fix a "major" network problem in the UK. I was initially to travel there but several things (lab prep being one of them) got in the way, so I wound up going the VPN route. The project had procured numerous Metro Ethernet links in the neighborhood of tens of kilometers each. Various adjacencies were able to establish over these links and moderate amounts of traffic were passed, but there was lots of jitter and high traffic loads just plain choked. These were 100 Mbps Ethernet segments. We all know that Cisco 10/100 ports default to half-duplex if auto-negotiation fails. Well, not *everybody* knows, or I wouldnbt have gotten that work! ;-) It was quickly revealed that the carrier's Metro Ethernet gear was hard-coded full-duplex and not participating in auto-negotiation. All of the switch ports were left at default settings and thus reverted to half-duplex. Major "collisions" were wreaking havoc on th!
e Cisco boxes. Since the two different devices were configured differently but administered by completely different organizations/individuals, this problem actually went on for some months. The carrier simply tested all of the links and told the customer the problem was in their network. The customer tested all of their gear and found it to be fine until they connected it to the Metro Ethernet service. Classic stalemate (aka "consultant's business opportunity").
-----Original Message-----
From: nobody@groupstudy.com [mailto:nobody@groupstudy.com] On Behalf Of Marko Milivojevic
Sent: Wednesday, November 12, 2008 3:19 PM
To: Town Tien
Cc: Radioactive Frog; CCIE Lab
Subject: Re: OT: Problem at work
On an equally serious note, duplex problems are something that is ery
easily overlooked. Especially in complex environments where so many
other things can go wrong... That particular problem can be cause of
endless pain and may not be as easy to pop-up in engineers' minds as
you may think :-).
On Wed, Nov 12, 2008 at 21:34, Town Tien <tientien.wang@gmail.com> wrote:
> Frog,
> Thx for the link, I think you missed my point. Being a senior guy,
> those are basic knowledge and is expected to understand. I didn't mean
> I spent hours and day to figure out it's a duplex issue. Althought
> it's a silly mistake, it has a huge impact on the network.(utilization
> double), cause hardware failure, triggered bugs. I will let you figure
> the steps I have to do to stabilize the network.
>
> Tien
>
> Sent from my iPhone
>
> On Nov 12, 2008, at 1:49 AM, "Radioactive Frog" <pbhatkoti@gmail.com>
> wrote:
>
>> I spent hours sometime day to fix up some of the mistakes my
>> senior engineer did. some of those mistake as silly as duplex mismatch
>> -----------------------------------
>>
>> Perhaps your seniors are more intelligent than you!!
>>
>> http://etherealmind.com/2008/07/15/ethernet-autonegotiation-works-why-how-standard-should-be-set/
>>
>> -frog
>>
>>
>> On Mon, Nov 10, 2008 at 8:36 PM, Tien <tientien.wang@gmail.com> wrote:
>> GS,
>> I have this problem at work, hopefully someone can give me some
>> advice or
>> guidance before i make an decision.
>> Im a network engineer for a local ISP operation team, my manager
>> oversee two
>> groups, one for internal IT desktop support and the other one is
>> for ISP
>> operation which i am in.
>>
>> Problem 1, the supervisor from IT team constantly step over and
>> trying to do
>> our jobs. there's nothing I can do, since he and my manager are really
>> close. I got really upset one time when he(IT guy) was represented
>> me for a
>> mpls project i am doing to our exec management meeting. When I
>> questioned
>> his involvement, my manager told me he just helping us out. This is
>> clear to
>> me, my role is just do the technical part and they will claims the
>> credit.
>>
>> Problem 2, I spent hours sometime day to fix up some of the
>> mistakes my
>> senior engineer did. some of those mistake as silly as duplex
>> mismatch. This
>> is a problem and my manager refused to address it, because they are
>> drinking buddy. :( What's worse is not only i have to take care of
>> my own
>> projects, my manager is able to make me finish the senior guy's
>> projects as
>> well.
>>
>> I dont think i have much options left beside move on and find
>> another job,
>> or comply with whatever thats going on and suck it up.
>>
>>
>> Any advice is greatly appreciated.
>>
>> Tien
>>
>>
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>>
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