Tuesday, December 28, 2010
grops: STP Loop GuardThe STP loop guard feature provides ...
grops: STP Loop GuardThe STP loop guard feature provides ...: "STP Loop GuardThe STP loop guard feature provides additional protection against Layer 2 forwarding loops (STP loops). An STP loop is..."
STP Loop Guard
The STP loop guard feature provides additional protection against Layer 2 forwarding
loops (STP loops). An STP loop is created when an STP blocking port in a redundant
topology erroneously transitions to the forwarding state. This usually happens because
one of the ports of a physically redundant topology (not necessarily the STP blocking port)
no longer receives STP BPDUs. In its operation, STP relies on continuous reception or
transmission of BPDUs based on the port role. The designated port transmits BPDUs, and
the non-designated port receives BPDUs.
When one of the ports in a physically redundant topology no longer receives BPDUs, the
STP conceives that the topology is loop free. Eventually, the blocking port from the
alternate or backup port becomes designated and moves to a forwarding state. This
situation creates a loop.
The loop guard feature makes additional checks. If BPDUs are not received on a non-
designated port, and loop guard is enabled, that port is moved into the STP loop-
inconsistent blocking state, instead of the listening / learning / forwarding state. Without
the loop guard feature, the port assumes the designated port role. The port moves to the
STP forwarding state and creates a loop.
When the loop guard blocks an inconsistent port, this message is logged:
loops (STP loops). An STP loop is created when an STP blocking port in a redundant
topology erroneously transitions to the forwarding state. This usually happens because
one of the ports of a physically redundant topology (not necessarily the STP blocking port)
no longer receives STP BPDUs. In its operation, STP relies on continuous reception or
transmission of BPDUs based on the port role. The designated port transmits BPDUs, and
the non-designated port receives BPDUs.
When one of the ports in a physically redundant topology no longer receives BPDUs, the
STP conceives that the topology is loop free. Eventually, the blocking port from the
alternate or backup port becomes designated and moves to a forwarding state. This
situation creates a loop.
The loop guard feature makes additional checks. If BPDUs are not received on a non-
designated port, and loop guard is enabled, that port is moved into the STP loop-
inconsistent blocking state, instead of the listening / learning / forwarding state. Without
the loop guard feature, the port assumes the designated port role. The port moves to the
STP forwarding state and creates a loop.
When the loop guard blocks an inconsistent port, this message is logged:
- CatOS
%SPANTREE-2-LOOPGUARDBLOCK: No BPDUs were received on port 3/2 in vlan 3. Moved to loop-inconsistent state. - Cisco IOS
%SPANTREE-2-LOOPGUARD_BLOCK: Loop guard blocking port FastEthernet0/24 on
grops: How hard is the CCIE lab, really?The lab is not ha...
grops: How hard is the CCIE lab, really?The lab is not ha...: "How hard is the CCIE lab, really?The lab is not hard. I know coming from someone with my history of making a few too many trips to the lab t..."
How hard is the CCIE lab, really?
The lab is not hard. I know coming from someone with my history of making a few too many trips to the lab that might be a hard statement for people to believe.
It's not "that" hard. It is "that" intimidating. If you have any doubts, it will make you soul-search, waste time validating or referencing a solution to something you already know the solution too, or just make you waste time searching for something you couldn't find or a task you could not perform if you had a week and not just a day.
It's easy to come close to pass the lab. It's a lot harder to work on your own to pass the lab in one's own fashion.
While it is true there are "labs" out there, I'd rather ask if someone gave a person a copy of any vendors lab and that person did not have the solutions guide or any assistance from the rest of our online study buddies, then how long would it take us to resolve any given lab with a score of 80% eventually providing the same expected solutions that the lab exam desingers did.
You see that is the meat of being a CCIE and passing the CCIE Lab.
The fact is different for most candidates and here are some examples:
1. I went to Networkers/Cisco Live and attended 2 techtutorials in 2009. Well aside from myself, a CCIE voice sitting next to me, and maybe 1-2 other CCIE RS Lab scarred veterans most of the people in the room could scarcely answer the majority of the questions. In the session with NMC, I don't think there was more than myself and "maybe" one other who could configure Frame Relay at all, much less on the fly and get 4-6 routers working in under 15 minutes for any protocol.
2. I went to a CCIE Beta Lab in Seattle. Of the 8 people there taking the lab, when there was an issue with Frame Relay, I was the only person who knew how to verify my Frame Relay PVCs. The only one. The other 7 would not have been able to build a core in a real lab environment, test it, and move on without looking back.
3. I've been to a lot of CCIE Bootcamps by now and first-timers (those who have not been to a bootcamp are usually left to leave the class in stun and awe... feeling terribly out of place most of the time). There are some few first-timers who actually completed entire workbooks of 1-2 vendors before coming to class - usually this means they worked through the solutions and used the solutions guides or... did not. Anyway they score in the 50-75 range usually if I had to give an average.
None of them are ready to sit the lab at that time and most are 3-6+ months or more off - easy.
4. I've also went to classes (or a class or two) where 1-2 students completed at least 1-2 workbooks mostly on their own, took their licks and bit their own pride... 2 of these people went to the CCIE Lab and passed on the first attempt. One of them could teach mostly any subject and the other blogged quite publicly about his experiences.
5. The rest of the people in the classes I observed had been to the lab 2-5 or even 6 times (most stop counting after 5 attempts it seems to me - they say... "I think I went to 4 labs" one day and then say "I went to 5 labs" when asked again or they'll just tell you they don't remember... Ouch!).
The worst part about the CCIE Labs is our own ego. That's really it. It is.
You see, we practice, we read, we blog, and we do it all over again. The truth is the people who pass the lab and do so on their own whether they do it one attempt ( by definition this should be rare... like lightening striking a person 3 times in a row in the same spot) or if they take several attempts... really know the material when they go to the lab and return victorious.
You see, to pass the CCIE Lab, and pass it on your own, without any sort of shortcut or cheat... there is no such thing as luck, only very very hard work.... these guys/gals know every cranny of the CLI for their respective track. They just do. There is no "I forgot"... It's just not in the vocabulary.
You see the people who pass the lab, either studied very hard to pass the first time. I mean to the extent they can pretty much get up and perform an impromptu lecture on any given topic.. or by the time they do pass the lab... that is exactly what a CCIE can do and is willing to do to prove and differentiate themselves from the chafe.
There may be a very few who slink by and passed without this level of knowledge but I'd have to believe that number is small, very small. Luck might be there for a few people, however, there is no such thing as luck, there is however a defined measure of skill and expertise.
This is why there is no such thing as a "Paper CCIE" and if you find one who isn't as I have described, then either that CCIE is playing dumb since you may have insulted him/her and won't play the game... or that person holds digits but is not a CCIE in the first place.
Some people pass the CCIE Lab and were not such as I decribed above. True. However, I have seen many of these folks earn the title of the CCIE and are quality engineers after the fact. I'll not divulge names to protect the innocent.
Me... I'm still a CCNP and I'm working on it. I can configure most stuff on the fly and for sure any basic config and verify it - sometimes even quickly. However, I'm still working on total mastery of the IOS and I am not sure I can beat Narbik's mastery of the CLI or have Scott Morris' glib tongue while trying to descibe every topic. I am getting closer to the prize for mostly every technology and I've offered my services as a tutor to up and coming network analysts and engineers specifically with the goal of attaining such final mastery. I'm working hard to make 2011 the year.
So is the lab hard? No, not to a properly prepared CCIE candidate who has showed up to earn the digits. Not at all.
It's not "that" hard. It is "that" intimidating. If you have any doubts, it will make you soul-search, waste time validating or referencing a solution to something you already know the solution too, or just make you waste time searching for something you couldn't find or a task you could not perform if you had a week and not just a day.
It's easy to come close to pass the lab. It's a lot harder to work on your own to pass the lab in one's own fashion.
While it is true there are "labs" out there, I'd rather ask if someone gave a person a copy of any vendors lab and that person did not have the solutions guide or any assistance from the rest of our online study buddies, then how long would it take us to resolve any given lab with a score of 80% eventually providing the same expected solutions that the lab exam desingers did.
You see that is the meat of being a CCIE and passing the CCIE Lab.
The fact is different for most candidates and here are some examples:
1. I went to Networkers/Cisco Live and attended 2 techtutorials in 2009. Well aside from myself, a CCIE voice sitting next to me, and maybe 1-2 other CCIE RS Lab scarred veterans most of the people in the room could scarcely answer the majority of the questions. In the session with NMC, I don't think there was more than myself and "maybe" one other who could configure Frame Relay at all, much less on the fly and get 4-6 routers working in under 15 minutes for any protocol.
2. I went to a CCIE Beta Lab in Seattle. Of the 8 people there taking the lab, when there was an issue with Frame Relay, I was the only person who knew how to verify my Frame Relay PVCs. The only one. The other 7 would not have been able to build a core in a real lab environment, test it, and move on without looking back.
3. I've been to a lot of CCIE Bootcamps by now and first-timers (those who have not been to a bootcamp are usually left to leave the class in stun and awe... feeling terribly out of place most of the time). There are some few first-timers who actually completed entire workbooks of 1-2 vendors before coming to class - usually this means they worked through the solutions and used the solutions guides or... did not. Anyway they score in the 50-75 range usually if I had to give an average.
None of them are ready to sit the lab at that time and most are 3-6+ months or more off - easy.
4. I've also went to classes (or a class or two) where 1-2 students completed at least 1-2 workbooks mostly on their own, took their licks and bit their own pride... 2 of these people went to the CCIE Lab and passed on the first attempt. One of them could teach mostly any subject and the other blogged quite publicly about his experiences.
5. The rest of the people in the classes I observed had been to the lab 2-5 or even 6 times (most stop counting after 5 attempts it seems to me - they say... "I think I went to 4 labs" one day and then say "I went to 5 labs" when asked again or they'll just tell you they don't remember... Ouch!).
The worst part about the CCIE Labs is our own ego. That's really it. It is.
You see, we practice, we read, we blog, and we do it all over again. The truth is the people who pass the lab and do so on their own whether they do it one attempt ( by definition this should be rare... like lightening striking a person 3 times in a row in the same spot) or if they take several attempts... really know the material when they go to the lab and return victorious.
You see, to pass the CCIE Lab, and pass it on your own, without any sort of shortcut or cheat... there is no such thing as luck, only very very hard work.... these guys/gals know every cranny of the CLI for their respective track. They just do. There is no "I forgot"... It's just not in the vocabulary.
You see the people who pass the lab, either studied very hard to pass the first time. I mean to the extent they can pretty much get up and perform an impromptu lecture on any given topic.. or by the time they do pass the lab... that is exactly what a CCIE can do and is willing to do to prove and differentiate themselves from the chafe.
There may be a very few who slink by and passed without this level of knowledge but I'd have to believe that number is small, very small. Luck might be there for a few people, however, there is no such thing as luck, there is however a defined measure of skill and expertise.
This is why there is no such thing as a "Paper CCIE" and if you find one who isn't as I have described, then either that CCIE is playing dumb since you may have insulted him/her and won't play the game... or that person holds digits but is not a CCIE in the first place.
Some people pass the CCIE Lab and were not such as I decribed above. True. However, I have seen many of these folks earn the title of the CCIE and are quality engineers after the fact. I'll not divulge names to protect the innocent.
Me... I'm still a CCNP and I'm working on it. I can configure most stuff on the fly and for sure any basic config and verify it - sometimes even quickly. However, I'm still working on total mastery of the IOS and I am not sure I can beat Narbik's mastery of the CLI or have Scott Morris' glib tongue while trying to descibe every topic. I am getting closer to the prize for mostly every technology and I've offered my services as a tutor to up and coming network analysts and engineers specifically with the goal of attaining such final mastery. I'm working hard to make 2011 the year.
So is the lab hard? No, not to a properly prepared CCIE candidate who has showed up to earn the digits. Not at all.
grops: How CCNA's get hired without experience by Darby W...
grops: How CCNA's get hired without experience by Darby W...: "How CCNA's get hired without experience by Darby Weaver1. Get experience. - Read Cisco Books - Cisco Validated Designs, SRND, Cisco Cu..."
How CCNA's get hired without
experience by Darby Weaver
1. Get experience.
- Read Cisco Books - Cisco Validated Designs, SRND, Cisco Customer Proof of Concepts, Steps to Success, and the list goes on for days. Pick a technology, read it, create a project plan and a simple set of checklists. Got more time, do the Visio diagrams, you can use these for templates later and always improve them as you get more experienced. The Cisco Discovery Series for the Cisco Academy - Simply Awesome!!! I just bought 3 sets myself.
- Join a local Cisco Study Group and Network (With Breathing People)
- Become a Subject Matter Expert on Cisco Forums (Lots to Choose From)
- Volunteer and Perform Network Related Tasks
- Offer Free Network Assessments and Advice
- Become a Speaker and Exhibit Your Hard-Earned CCNA Skills to Potential Employers
- Offer Help to Friends and other Students Seeking a CCNA - Help them study, build, and configure labs for example.
- Register with a temp agency - and mention you are a CCNA (any Cisco work WILL find you).
- Get a small lab and live the career you want to become... I do it too.
2. Learn more.
- Learn to communicate.
- Learn how to get a job.
- Learn how to create checklists.
- Learn how to do research.
- Learn how to find things and find them fast.
- Learn how to listen.
- Learn how to attend meetings.
- Learn how to speak properly with peers.
- Learn how to make and awesome first and lasting impression.
- Learn your tools like MS Office, Visio, and Project
- Learn what is expected of a network manager.
- Learn everything else I didn't tell you and neither did your instructor.
- Learn how to use than Sniffer.
3. Apply what you learn.
- Volunteer...
- Go door to door in your neighborhood and offer to help people with their network, wireless, or modem.
- Go to your church or community centers and offer to help with their network.
- Go to local businesses and offer to be of assistance with their networks.
- Put an add in your local paper and offer to perform network related tasks for free or low cost.
4. Go and get paid...
- CCNA's might seem in abundance on the Internet however in reality they are still rather scarce. So you have to meet me half way and APPLY FOR THE JOB.
- Any CCNA worth his salt can basically go door to door and find work.
- If you can't find work at $250.00 per hour, then consider charging less, maybe the prevailing rate in your neck of the wood is $25.00 per hour or more... perhaps less.
- Hint: Most consultants need to earn at least $50.00 per hour to remain viably employed and pay their own employment taxes here in the USA.
5. If you are really having that hard of a time... track me down... email is best but I have a phone number too...
- I offer my own consulting and guidance for free if I have the time...
- If you need my time when I don't have the time - I do charge $150.00 per hour or so... might be the best one hour you ever bought...
FYI -
I don't make this stuff up...
When I left the military in 1994, I found a computer repair shop and I offered my services... for FREE. I told the guy I'd do ANYTHING to be of service - just to hang around.
Charles Thorpe was the man's name and he looked at me... cautiously and thought about it. Then told me to come in the next day.
For three months, I ran errands, cleaned up the shop, made the coffee... ran to buy stuff, deposit money for him... literally anything he asked... I did it.
In those three months, I learned to build my very first IBM PC. Yep... that's how it happened. The AMD DX2-80 was quite the powerful upgrade from my IBM PS1 SX25 Consultant.
I was happy with the bargain, but I needed to go to work to earn some cash so... I did a few of my own jobs and put my shingle out at a whopping $15.00 per hour and buddy business was a booming... I got little 50 hour projects and such and it was working out.
Charles asked me to come back and this time offered to pay me $5.00 or so per hour to hang out when I could and be the gopher again. This time I was fixing more and more things too. But I was still a padawa...
One day I told Charles I'd be ready in about 6 months or so. He needed an expert now! at the time. So it was what it was...
Then one day a doctor came into the shop and needed help with his computer and really with his network. Well Charles' business was called "Computer Depot" and not "Network Depot" and I did have some "Network Experience" from the Navy... so the good doctor and I were speaking in Spanish and he was not happy waiting (umm... he was the doctor) and he gave me a number and invited me to help him out.
So... Not even 6 months into the game I got my first networking gig. I charged an outrageous $35.00 per hour and I earned over $3500.00 that month on the doctor's network - most of it in just a single week networking 7 PC's with Artisoft's Lantastic which is what I just so happened to be running at my house at the time on 6 PC's I called servers...
WoW!
So there's one of my rules put into action with awesome results... And that my friends is a very true story.
I did the paper thing and even ran fliers literally door-to-door... and you know it worked for me... 400 clients in about 3+ years... till I went to work at City Hall in Orlando on a contract.
BTW - 100 Fliers produced about 3 clients each worth about $150.00 each on average or about 4 hours of work and I usually got them within 24 hours of the walking the fliers...
It's kind of kewl... Walk the fliers on the weekend and FEAST for the week...
That's my door-to-door success story.
I tell everyone I know that if I became unemployed in the corporate world today... I would never starve...
Mind you I was doing all this with no certs, no formal training, and only my will to work and do a better job than anyone else - my guarantee was "No Fix, No Pay" and baby... I got paid!
So... the volunteer thing.... I did that one too...
And ya know what? If worked too... It did.
I got a call from the American Red Cross after volunteering and making a good impression of course...
They had an emergency... I now had my CCNA (actually I passed it twice as the exam changed in the 6 months period which I took it).
So I had to take a day off of work and come to the rescue... at $1,000.00 per day...
I earned $17,000.00 total for that bit.
The list goes on and on...
A CCNA is a formidable, reputable, certification and is worthy of $$$ if you can walk the walk...
- Read Cisco Books - Cisco Validated Designs, SRND, Cisco Customer Proof of Concepts, Steps to Success, and the list goes on for days. Pick a technology, read it, create a project plan and a simple set of checklists. Got more time, do the Visio diagrams, you can use these for templates later and always improve them as you get more experienced. The Cisco Discovery Series for the Cisco Academy - Simply Awesome!!! I just bought 3 sets myself.
- Join a local Cisco Study Group and Network (With Breathing People)
- Become a Subject Matter Expert on Cisco Forums (Lots to Choose From)
- Volunteer and Perform Network Related Tasks
- Offer Free Network Assessments and Advice
- Become a Speaker and Exhibit Your Hard-Earned CCNA Skills to Potential Employers
- Offer Help to Friends and other Students Seeking a CCNA - Help them study, build, and configure labs for example.
- Register with a temp agency - and mention you are a CCNA (any Cisco work WILL find you).
- Get a small lab and live the career you want to become... I do it too.
2. Learn more.
- Learn to communicate.
- Learn how to get a job.
- Learn how to create checklists.
- Learn how to do research.
- Learn how to find things and find them fast.
- Learn how to listen.
- Learn how to attend meetings.
- Learn how to speak properly with peers.
- Learn how to make and awesome first and lasting impression.
- Learn your tools like MS Office, Visio, and Project
- Learn what is expected of a network manager.
- Learn everything else I didn't tell you and neither did your instructor.
- Learn how to use than Sniffer.
3. Apply what you learn.
- Volunteer...
- Go door to door in your neighborhood and offer to help people with their network, wireless, or modem.
- Go to your church or community centers and offer to help with their network.
- Go to local businesses and offer to be of assistance with their networks.
- Put an add in your local paper and offer to perform network related tasks for free or low cost.
4. Go and get paid...
- CCNA's might seem in abundance on the Internet however in reality they are still rather scarce. So you have to meet me half way and APPLY FOR THE JOB.
- Any CCNA worth his salt can basically go door to door and find work.
- If you can't find work at $250.00 per hour, then consider charging less, maybe the prevailing rate in your neck of the wood is $25.00 per hour or more... perhaps less.
- Hint: Most consultants need to earn at least $50.00 per hour to remain viably employed and pay their own employment taxes here in the USA.
5. If you are really having that hard of a time... track me down... email is best but I have a phone number too...
- I offer my own consulting and guidance for free if I have the time...
- If you need my time when I don't have the time - I do charge $150.00 per hour or so... might be the best one hour you ever bought...
FYI -
I don't make this stuff up...
When I left the military in 1994, I found a computer repair shop and I offered my services... for FREE. I told the guy I'd do ANYTHING to be of service - just to hang around.
Charles Thorpe was the man's name and he looked at me... cautiously and thought about it. Then told me to come in the next day.
For three months, I ran errands, cleaned up the shop, made the coffee... ran to buy stuff, deposit money for him... literally anything he asked... I did it.
In those three months, I learned to build my very first IBM PC. Yep... that's how it happened. The AMD DX2-80 was quite the powerful upgrade from my IBM PS1 SX25 Consultant.
I was happy with the bargain, but I needed to go to work to earn some cash so... I did a few of my own jobs and put my shingle out at a whopping $15.00 per hour and buddy business was a booming... I got little 50 hour projects and such and it was working out.
Charles asked me to come back and this time offered to pay me $5.00 or so per hour to hang out when I could and be the gopher again. This time I was fixing more and more things too. But I was still a padawa...
One day I told Charles I'd be ready in about 6 months or so. He needed an expert now! at the time. So it was what it was...
Then one day a doctor came into the shop and needed help with his computer and really with his network. Well Charles' business was called "Computer Depot" and not "Network Depot" and I did have some "Network Experience" from the Navy... so the good doctor and I were speaking in Spanish and he was not happy waiting (umm... he was the doctor) and he gave me a number and invited me to help him out.
So... Not even 6 months into the game I got my first networking gig. I charged an outrageous $35.00 per hour and I earned over $3500.00 that month on the doctor's network - most of it in just a single week networking 7 PC's with Artisoft's Lantastic which is what I just so happened to be running at my house at the time on 6 PC's I called servers...
WoW!
So there's one of my rules put into action with awesome results... And that my friends is a very true story.
I did the paper thing and even ran fliers literally door-to-door... and you know it worked for me... 400 clients in about 3+ years... till I went to work at City Hall in Orlando on a contract.
BTW - 100 Fliers produced about 3 clients each worth about $150.00 each on average or about 4 hours of work and I usually got them within 24 hours of the walking the fliers...
It's kind of kewl... Walk the fliers on the weekend and FEAST for the week...
That's my door-to-door success story.
I tell everyone I know that if I became unemployed in the corporate world today... I would never starve...
Mind you I was doing all this with no certs, no formal training, and only my will to work and do a better job than anyone else - my guarantee was "No Fix, No Pay" and baby... I got paid!
So... the volunteer thing.... I did that one too...
And ya know what? If worked too... It did.
I got a call from the American Red Cross after volunteering and making a good impression of course...
They had an emergency... I now had my CCNA (actually I passed it twice as the exam changed in the 6 months period which I took it).
So I had to take a day off of work and come to the rescue... at $1,000.00 per day...
I earned $17,000.00 total for that bit.
The list goes on and on...
A CCNA is a formidable, reputable, certification and is worthy of $$$ if you can walk the walk...
grops: How To Create A New FaceBook Community Or Group ...
grops: How To Create A New FaceBook Community Or Group
...: "How To Create A New FaceBook Community Or Group To start with : 1 You should have an account with facebook and in case if you don’..."
...: "How To Create A New FaceBook Community Or Group To start with : 1 You should have an account with facebook and in case if you don’..."
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