Long time, no post.

Hello Everyone,

I haven’t posted in quite some time, as I’ve been studying quite a bit in either anything Network related or anything related to my current enrollment in college. Working on my BSIT – Information Security and Assurance. I may be keeping things short and to the point as of late, with the newest addition of my family set to arrive in August, 2011. Another boy!, making that 3 strikes on the little girl. I guess I’m out, but not according to my wife.

Anyway, I wanted to talk a little bit about an interesting problem I was presented with from a friend of mine. He was setting up a 2 link ether-channel on a Cisco 4500 series and ran into an interesting issue. You can see in the image below that the link actually negotiated what looks like a sub-interface on the ether-channel.

LACP sub-interface negotiation

This was a little odd, as I’d never seen an ether-channel negotiation produce a sub-interface. So I did a little bit of digging and found some interesting information on what could have possibly happened.

It seems that the alpha-numeric number/letter combination assigned to the Po19A does indeed indicate a mis-negotiation of the link on the end of the 4500. I would imagine that this could be anything from a Speed / Duplex mismatch to STP finding it as a “redundant” link and causing it to re-negotiate the link on the fly. This, of course, would all be done using LACP, as this is the protocol that is used for negotiating a Link Aggregation that isn’t statically configured. I wasn’t able to produce this on my lab equipment, though I am still trying occasionally. If anyone reads this and has any possible insight as to what could have caused this, it would be greatly appreciated. For now, I will stick to my own hypothesis.

On a different note, I was able to take and pass my CCNA exam on May 11, 2011. I passed with a score that makes me happy and with a considerable amount of time left, so I definitely feel accomplished on that end. I also picked up the CCNP Certification Library for around 100 dollars off of Amazon.com – much to my wife’s dismay. I get the feeling she thinks I bury my head in too many books and spend too many hours in my dungeon while teaching myself all of this information. But she has been incredibly supportive, so I cannot complain.

CCNA Crest

I plan to keep updating this as I progress through my CCNA Security and CCNP and all the way to CCIE, studies. I will also update it with little tid-bits of things I learn or stump me in the field to see if I can get anyone’s opinions on these matters.

Until Next Time,



2 thoughts on “Long time, no post.

  1. Be thankful for a supportive spouse, its a rare gift. I made the same journey from CCNA through CCIE and it was quite the trek. If you need any help alon the way feel free to let me know…

    • Thank you very much! I am extremely grateful for my wife and she is very supportive. I am studying for the ROUTE exam right now and I will probably be taking it within the month or so. The nice thing is, once you study and learn the structure of how to study for Cisco certifications, it makes it a little quicker as you go through the next steps. 🙂

      Also, I will take you up on that if I ever have any questions.

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