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Posts Tagged ‘learning’

Dealing With Knowledge Gaps

January 6, 2011 2 comments

Inevitably, we are all going to come across things in our jobs that we are deficient in. Maybe we know a little about a certain topic, but we need to know more. Maybe we know absolutely nothing and need a basic introduction to the topic. Regardless, there will come a time in which we need to increase our knowledge and understanding of something in this ever growing world of networking or just IT in general.

The problem as I see it, is how I go about filling in those gaps. When you just start out in the IT world, you may not have a good methodology in which to learn about IT things. If you have been in the industry for a long time, you may already have a good system that works for you. No matter which category you fall into, the fact that you will constantly have to learn is unavoidable. There are NO exceptions to this rule. If you wish to be at the top of your game in IT from a technical standpoint, you must make a habit of constantly learning new things. Failure to do so means that your knowledge will become dated and you will drift off into obscurity working as some corporate slave in a dark and dreary cubicle. This may or may not involve working for the government. 🙂

Now that we have established that static knowledge is a dead end, let’s look at how to ensure we are always at the top of our game. I offer you the 5 step plan. Others have 12 step programs. Maybe some have less. I only have 5. I am all about efficiency…..and my program doesn’t cost you a dime.

1. Examine your current level of knowledge. – How much do you already know about the subject in question? The answer to that question is going to dictate the kind of resources you use. Let’s use BGP for example. If you need to learn about the basics of it, there are a few good books that can handle that. There are also plenty of websites with white papers and blog posts that give a generic overview of BGP. There are some classes out there that will accomplish the same thing. However, there are quite a few books and white papers that will completely blow your mind if you don’t already have a decent understanding of BGP. The service provider side of BGP comes to mind. Enterprises and service providers use BGP in VERY different ways.

2. Find out where the information is. – For starters, you need to identify what kind of learner you are. Some of us are visual learners. Some of us are audible learners. Some of us learn by doing. Perhaps you are a mix of several different methods. Only you know what works best for you. If you need a lot of pictures and the topic is relatively mainstream, maybe a visual CBT(computer based training) course is what you need. If that is the case, I highly recommend you check out CBT Nuggets. If what you are looking for is somewhat more obscure, then I would recommend asking other people who do what you do. There are a variety of resources in which you can ask these questions like LinkedIn, forums, or Twitter. I prefer Twitter because it is a lot quicker. The only possible problem would be having enough people see the request. If you are new to Twitter, or very rarely use it, you may not have many followers who would see your message. Feel free to engage others in a substantive manner and over time your followers will grow. If all you do is tell everyone what you ate for lunch or what the weather is like in your part of the world, you probably aren’t going to get anywhere. If you absolutely refuse to use something like Twitter, then consider posting on Cisco’s forums if your issue is of a Cisco nature or networking-forum.com. There are other forums out there as well as mailing lists(NANOG comes to mind). All of the major vendors have support forums as well. Keep in mind that you may have to sift through tons of information before you finally find the information you are looking for. There is not always going to be a technical paper or book that explains exactly what you are looking for. Sometimes you have to piece it together from multiple sources. Actually, I would recommend that you use multiple sources unless it is some vendor specific thing that you can only get in one place. I have found out that you cannot trust a single source for 100% accuracy. Not that all sources are wrong, but imperfect human beings write books, white papers, and blog posts. Other imperfect human beings double check these same sources. When the content is of a technical nature, things get missed. This is especially true for the deeper technical things.

3. Execute. – You have all of the appropriate resources identified. Now you just need to get that information into your head. There are no shortcuts. While I wish I could learn kung-fu like Neo did in The Matrix, it isn’t going to happen. You have to put in the time required to absorb all of that information. Sometimes it can be done in a matter of minutes. Sometimes it takes weeks.

4. Ignore any distractions. – In the course of your learning, you are bound to come across something else that is interesting or neat. Resist the temptation to get sidetracked and stay focused on the main thing you are trying to learn. If you want to go back at another time and research the other items that pop up, then make a note of them. By focusing on the main thing you are trying to learn, you have a better chance of retaining information then if you start going in 100 different directions with every new thing that appears.

5. Allow the information to digest. – Sometimes it helps to simply think about things. Just go over it in your head. I tend to do this in conjunction with step 3. If I need to absorb a large amount of information, I like to take it in pieces and digest it little by little. By stopping to sort things out in your head, you can really come to terms with what makes sense and what doesn’t. I am very thankful my current employer allows me the freedom to do this. While it may look like I am spacing out on any given day in my cubicle, lots of times I am just thinking about something I just read or watched. It’s my way of performing a “write memory” on my brain. One of the other things I will do is drive to and from work in complete silence. That really helps because all I have to focus on is not crashing the car, which is relatively simple.

**Note – When asking others about a certain technology or product, do yourself a favor and research it first. Try and figure some things out on your own. This isn’t so much a problem with people who have been in the industry for a number of years as it is with those who have only been in IT for a few years or less. It’s not that people don’t want to answer the question. There will always be someone who will just blurt out an answer. The issue with asking without having done any research on your own is that you miss out on a great opportunity to develop your own research methods. There’s a reason that lmgtfy.com was created and is often quoted on Twitter. It has been my experience that those who last in IT are the ones that only need a nudge in the right direction. They don’t want their hand held. They just want a sanity check every now and then. The people who never want to put in the time or effort to figure something out and habitually want you to solve their problems are the ones that won’t make it in the long run. Well, they might have a job, but they won’t be anywhere near what they could be if they put forth some effort.

I am not going to make the bold claim that the 5 steps I laid out will work for everyone. They work for me when I follow them, and I don’t always follow them. I find the instances in which I have tried to cram something new into my head without following these steps ends badly. I forget something and have to start all over again. When I take the time to really dig into something and not rush it, it tends to stay with me at least from a conceptual point of view.

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Chasing the “Ah-ha!” Moments

December 20, 2010 9 comments

Image courtesy of Wikipedia

Whenever I talk to people who are just getting started in networking, there’s a part of me that wishes I was in their shoes. I say that because I know several of the things they are going to learn or figure out in the next couple of years and I remember having to go through the same process. Before I understood variable length subnet masks(VLSM), the numbers in the subnet mask field of a workstation’s TCP/IP settings didn’t really mean a whole lot to me. If someone used slash notation(ie /24, /16, /27), I had no idea what that meant. Like a lot of people, I relied on someone to tell me what the subnet mask was. However, once I learned about VLSM, it was as if a whole new world opened up. That was one of my absolute favorite “Ah-ha!” moments. You’ve had those yourself haven’t you? It is the point in time in which a certain technical concept just clicks in your head. You go from not really understanding it, to comprehending it. In fact, it’s almost as if that concept is only represented in binary inside your head. You go from a 0 to a 1 with no in between.

As you progress along in networking, more and more of these “Ah-ha” moments come. Unfortunately, over time they become fewer and fewer. That’s not to say that they go away completely. They don’t. They are just harder to come by. I’ve found that I am able to keep a steady stream of these “Ah-ha” moments coming as long as I look at technology without taking anything for granted. What I mean by that is that I don’t assume anything when it comes to trying to understand a protocol or technology. What I “think” I know might actually be wrong. My understanding might only be partial. I have to continually ask “why/what/how/when/where” when dealing with technology.

Let me give you a personal example. I have known for many years that a T-1 is 1.544Mbps in terms of bandwidth. It is comprised of 24 64kb channels. The only problem is that 24×64,000 is 1536000 and not 1544000. Oops. Where did the other 8k go? To further drive this home, a “show interface” on a serial link that is configured as a full T-1 shows the interface bandwidth to be 1536kbps. Why the discrepancy? I could have just moved on and ignored the reason behind the discrepancy. However, by researching the issue and figuring out what the issue with this discrepancy was, I learned a whole lot more about T-1’s. I learned how alarms over the circuit get propagated. I learned what the extended super frame(ESF) actually was. In other words, had I not been curious as to why the math didn’t add up when it came to T-1 bandwidth, I would be far more deficient in the inner workings of the T-1.

In the spirit of chasing the “Ah-ha” moments, take a look at the 4 questions below. Go find the answers if you don’t already know them.

1. Why is MPLS faster than conventional IP based routing?
2. What are the differences between a multi-layer switch and a router?
3. Why do you need different antennas for wireless access points and where would you use each antenna type? Sure, this is rather open ended, but what I am getting at is the radiation pattern of each antenna.
4. How does traceroute really work? Not just the TTL mechanics, but look at the various ICMP type codes as well.

Can you remember the last “Ah-ha” moment you had? If not, why? If so, does it make you want to go out and find more of those moments?

The Many Hats of the Network Engineer

November 18, 2010 8 comments

Remember when the network field wasn’t so complicated? Think back to the early 1990’s. Wireless for enterprise users was in its infancy. Firewalls seemed to be a bit easier to administer. Virtualization was limited to the mainframe community. A T-1/E-1 cost a billion dollars a month and could provide Internet connectivity for thousands of users. Voice was still confined to its own cable plant and the PBX was humming along using TDM. RIPv1 was still pretty popular. Hubs made packet captures easy to obtain, but broadcast storms constantly took down segments of the network. Storage involved connecting an external disk array to a server via a SCSI cable. ISDN was what the rich people used at home for Internet access. You know. The good old days.

Well it seems that a lot has changed since then. While I have no desire to go back to those days, I do miss the simplicity. Or at least what seems simplistic compared to today. Let’s take a look at what your typical enterprise network person has on their plate. Keep in mind that in some environments, these people also have systems related duties such as Active Directory administration, Linux/Unix administration, e-mail, database, etc.

Routing – Static, OSPF, EIGRP, and BGP

Switching – STP and its variants(RST, MST, PVST), Link aggregation(port channels/etherchannels)

Wireless – AP’s(antenna types), controllers, extras(location services, management), 802.11a/b/g/n

Circuits/WAN – T-1’s, DS-3’s/T-3’s, OC-3/12/48(SONET), Metro Ethernet, ISDN(Yes, it’s still out there), FrameRelay(Yep. That one too.), MPLS

Voice – call routing, phone(station) administration, voice mail, conferencing(audio and video), PRI’s, DID’s, signaling, codecs, voice gateways

Other Services – Multicast, load balancing, firewall, IPS, VPN, WAN optimization, content filters(web,e-mail), network management platforms, QoS, packet capture analysis(ie Wireshark,tcpdump), storage networking

Does that about sum it up? Yes, some of those things were being done back in the 90’s and in some cases, even earlier. However, a lot of them are relatively new things. Maybe you don’t have to touch all of those things. Maybe you do. For some of the service provider type things (MPLS, SONET), you may not ever have to administer that end, but if you’re buying those services, you better be familiar with them. Perhaps your organization is large enough to break out the security side of things or the voice side of things. Maybe you have a dedicated storage group that handles the storage network side. If you are lucky, you may even have a dedicated wireless engineer or two depending on the size of your wireless deployment.

It is a monumental task to become proficient in all of those areas, but wait; there’s more. For many people in the network space, they also have to become data center/facility engineers focusing on the following things:

Monitoring – temperature, humidity, water leak, smoke, power load levels

Cooling – BTU calculations, hot/cold aisle design, airflow on hardware

Power – Circuit requirements, UPS requirements, generator requirements

Cabling – Sub-floor, above the rack, CAT-5/6/7 differences, patch panel choices/locations, SM and MM fiber differences

Space Requirements – Rack deployments, 2 post, 4 post, full height, half height

Think that’s all? Well, the past few years have added some additional requirements, and more are coming. Things such as:

Virtualization – It has been around for at least 5 years now in enterprise environments. It’s not going away and without using newer hardware/software from networking vendors, you can’t see what’s going on inside the server farm.

The Return to Layer 2 in the DC – TRILL and every vendor’s particular flavor of it aim to resolve the ineffiencies of Spanning Tree and turn your network switches into an intelligent fabric. This will be similar to what storage networks have today via Fiber Channel.

Consolidation of Storage and Data/Voice Traffic – It happened to voice about 10 years ago. Now it is happening to storage. Everything will be on 1 wire in a matter of years.

Traditional Endpoint Death – No longer will the phone, desktop, and laptop rule the network. Cellular phones, tablets, and other similar compact devices will show up on the wireless networks in even greater numbers than they are today. Congratulations corporate wireless person. You just become a Google, Apple, Microsoft, Blackberry, HP, Cisco, and Avaya engineer for their mobile product set.

IPv6 – And you thought planning IPv4 deployments were interesting? The migrations to IPv6 are going to be interesting. Using NAT and 6to4/4to6 tunnels will become commonplace until the IPv4 is gone. I realize this is already happening/happened in many other parts of the world. However, in the US, there’s still a LOT of work to be done.

Now I realize that nobody is going to be an expert in all of these areas. I also know that many employers are not going to require you to even be familiar with all of these things. With things like hosted data centers, you may not ever have to deal with data center build out. Power and cooling may never be an issue for you. I also know that there are plenty of good consultants out there that specialize in one or more of these areas. Of course, nobody stays at the same company forever, so what you do at company X today doesn’t mean you won’t do a bunch of other things at company Z tomorrow. I guess the point I am trying to make is that our jobs are only going to become more complex in the years to come. The amount of hardware we use may decrease, but the functions within that hardware will increase. I can see a day in which something like WAN optimization is built into the router itself, and I don’t mean via a service module. I mean built into the processors or ASIC’s themselves. Of course, that’s assuming we’re still using TCP at that time. I don’t even want to contemplate what wireless will be like after 802.11n because it makes my head hurt just trying to understand how 802.11n works today with multiple antennas.

Start looking at the blueprint for something like a Cisco CCIE Route/Switch(Insert any other track as well) or Juniper JNCIE exam and you’ll find that it only covers a portion of what you need to know in this day and age. Anyone who has been involved in that process from start to finish knows how much information you have to know to pass. For those who don’t know, it is a TON. Yikes! Still want the job? Maybe becoming a specialist isn’t such a bad idea after all.

Busy, Busy, Busy!

September 14, 2010 2 comments

It’s not that I don’t have anything to say! People who know me know that I very rarely shut up for more than a few minutes. It’s just that I have been fairly busy lately. A lot of different things have been eating into my time and writing things for a network blog take a lot of time and effort. I have a 4 day Cisco ACE class next week in which I will be out of town, so I hope to get several posts done at night when I am sitting in the hotel. You don’t actually think I will be going out at night do you? Hmmmm…..a week away from the office and a training day that ends at 4:30pm. That leaves me all sorts of time for the following:

1. Catch up on the billion or so web pages I have bookmarked.
2. Get some things written for the blog that revolve around possible competitors to the Nexus 7000. With HP, Arista, Brocade, Force10, and Juniper selling competing products, there’s a lot of data to sift through. I honestly have no idea who will come out on top. It might just be the Nexus 7000!
3. Comment on my experience with the ACE class I will be taking with Global Knowledge. I’ve spent the last several days at work focused on ACE, so I am very interested in filling in the gaps of my knowledge regarding this interesting product.
4. Read up a little more on the Cisco/EMC/VMware vBlock concept. I went to a presentation today about that and am intrigued to say the least.
5. Write about the concept of baselining your in-house applications. This would be focused on knowing what the normal TCP/UDP operations look like from a packet capture standpoint.

I try and keep a running list in Evernote of the things I would like to write about. The list continues to grow, but the time it takes to transform just one of those ideas into a somewhat coherent post just hasn’t been there.

I hope to have some new content up early next week. The last thing I want is to end up abandoning this blog and waste all my time playing mindless games on my iPad, although I do enjoy doing that a few times a week.

Make Your Job Easier

****Note – While I thought about detailing the technical steps necessary for delegation on different pieces of equipment, I decided to go with the more “architectural” or “philosophical” approach in this post. Besides, there are plenty of others out there who do a far better job with graphics and CLI examples.

Recently, I took some steps to make my job a little easier. I delegated access to another group that does not normally have anything to do with the network side of the house. In this particular instance, I was able to give that group access to a Cisco ACE load balancer. Normally, giving non-network people access to equipment would be frowned upon. This is especially true for equipment in a data center that controls data flows for your most important applications. I had to consider the following:

1. Can I give them specific levels of access?
2. Will they be able to perform operations with relative ease?
3. Does it make sense to do this?

Question 1 was easy. Of course we can provide granular levels of access. It is hard to find a piece of equipment on most enterprise networks that can’t do this. Question 2 was a “most likely”, but could have been tough if everything needed to be done via CLI. Question 3 was probably the most important. Generally speaking, most technical problems can be solved given enough time and resources(ie people, money, and equipment). What many of us should ask, and some of us fail to ask, is whether or not we SHOULD do something. I for one love playing with new equipment. Build an Ethernet switch that interfaces with a toaster and I want to play with it. However, is there any use for something like that? Is there a large community of people out there that want connectivity with their toaster?

The point, is that while a lot of things are possible, not everything is necessary. Sometimes giving people access to network equipment can cause more harm than good. While I am a big fan of wanting to provide as much information to others as possible, if that information cannot be interpreted correctly, you are wasting your time. For example, I have been in environments where non-network related groups were given access to Netflow data. While that sounds great on the surface, the reality was that the data was being interpreted incorrectly. When looking at something like a 3Mbps circuit, some people would see full utilization and assume that more bandwidth was required. What they failed to take into account was that the QoS markings of the traffic indicated that a bunch of AF11(what was deemed scavenger) traffic was using the bulk of the bandwidth. Had any additional traffic come over the circuit that was tagged as AF21 or higher, it would have pushed down the AF11 traffic and gradually used more and more of the circuit until it reached the bandwidth limit that was set for that specific class of traffic. More bandwidth was not needed when the Netflow data was viewed in its entirety. Had this particular group understood QoS markings, they would have come to a different conclusion. Could we the network group have provided more in depth training on this particular product? Sure, but how long would that training have to be before the individuals understood QoS well enough to interpret traffic flows correctly? If you are a QoS fan, how long did it take you before you understood things like shaping vs policing? Or L2 vs L3 markings?

Back to the issue at hand. Does it make sense to give another group access to the load balancer? Yes. In this case it did. The typical process for maintenance on a server getting requests via the ACE load balancer was to have the network group pull it out of the active pool. Then, another group would make whatever changes were needed. Once they were done, they would contact the network group who would place the server back into the pool. If you are having to make changes to a dozen servers, this process can take some time. Why not just give the group making changes to the server limited access to the load balancer so they can do everything themselves? Time and resources would be saved by all.

That brings me back to the second question of can we make it easy for them to make changes to the load balancer? In the case of Cisco ACE, yes. We had an instance of Application Network Manager(ANM) running in our data center to help us. While I tend to be a fan of CLI (except in the case of the Cisco ASA), not everyone else is. Sometimes a GUI is far more helpful for people who need to make changes to network gear. That’s where ANM comes in. In a matter of minutes, I was able to create a domain(which is where you define the servers and farms you are giving access to), and role(you can create your own if you don’t like the default ones) for this other group to use. Now they had access to select servers and their corresponding server farms, but not enough access to do any real damage.

After doing that, I just had to create some instructions for the 2 tasks they would need to do. First, they need to know how to remove servers from a load balanced pool. Second, they need to know how to add servers to a load balanced pool. With ANM and the specific domain/role I assigned to their group, this is a piece of cake. I took the appropriate screen shots to walk them through the process of adding and removing a server and put it in a nice concise MS Word document. There are times when I am hesitant to put a lot of pictures in instructions. Sometimes people get offended when you drop it down to an elementary school level. Thankfully this particular group LOVED pictures, so everything worked out. In about 15 minutes we ran through the instructions. Additionally, I asked if they wanted a bit more detail about the Cisco ACE load balancer in general, so we talked about what it does and where it sits in terms of its physical place in the network. Everyone seemed happy with the training, and I think they were truly excited about not having to wait on the network group anymore when they needed to make changes.

Problem solved. Everyone was happy, and I know that outside group is reaping the benefits of being able to make changes on their own. I have jumped on to conference calls several times recently and noticed that servers were being added to and removed from load balanced pools without the network group having to do anything. The group I gave access to was taking care of it.

If you have the means to delegate processes to other groups, I would recommend that you do it provided it complies with any security and administrative policies your company or IT department has. You do have those policies in place right? 😉 If it makes your job easier, makes other people’s jobs easier, and you get to impart some knowledge about the network to external groups, why not do it?