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My IT Certification/Continuing Education Saga


V.T. Eric Layton

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V.T. Eric Layton

One thing I have going for me is that tests have never intimidated me. I don't freeze up or panic while taking tests. If I know the material, I can pass any test. Even if I just understand the basics, I can usually muddle through to a passing grade. I guess well. ;)

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One thing I have going for me is that tests have never intimidated me. I don't freeze up or panic while taking tests. If I know the material, I can pass any test. Even if I just understand the basics, I can usually muddle through to a passing grade. I guess well. ;)

Guessing well is half the battle with most things isn't it?
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V.T. Eric Layton

Well, we're still trying to gobble up a semester+ worth of material in 26 four hour sessions. It's proving interesting. Some thing are beginning to gel. I'm getting more comfortable with the Cisco IOS command line.

 

The last 30 mins or so of class today, we answered (or tried to, anyway) about 15 or so sample ccna type test questions. A few of them were UGLY thinker type scenario questions... "If SW1 is connected to port 22 or Router4 and the default port setting is being used, what is the bla-bla-bla... and how does this affect level 2 frame size?" There were even a few of these the the instructor answered incorrectly. ;)

 

Well, guess what I'm going to be doing this weekend? Yup... STUDYING, STUDYING, STUDYING!

 

Oh, and tomorrow we're not even covering any CCNA stuff. The resume/interview coach lady is coming in to teach us how to get a job. ;)

 

G'night all...

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V.T. Eric Layton

Resume Lady was... well, she was... bubbly, informative, helpful, etc. :)

 

We're (the class) just not so sure how all this psycho-babbly, self-help, feel-good, hugs-all-round stuff is going to help get us a job. We'll see...

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I've sat through one of those.... unfortunately, these folks giving the advice are the liberal arts/humanities majors who have no real experience in the field they are applying for. In your case, you have significant experience in a field that gives you skills absolutely vital to the field you are looking at.

 

The best advice I have is to tailor your resume to the job you are going for. Highlight the skills you have acquired both recently and in the past.

 

Example: You have experience in electronics repair. This makes you very methodical when troubleshooting problems using a precise analytical approach. On a resume for a networking company or IT department, highlight the problem solving skills you have acquired.

 

Also, I bet employers are looking for a resume that is simple and clear. No flowery language, and no "magic phrases." You have skills. Let those skills speak for themselves.

 

Adam

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V.T. Eric Layton

Yup. That's pretty much it, Adam. :yes:

 

=====

 

Anywho...

 

I just wanted to jump on here real quick-like and say howdy. I've been studying, studying, studying all weekend so far. Today's absolute must-do challenge was to learn how to subnet mask. I've almost got it, I think. I'm off to do a few more practice exercises.

 

Later all...

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V.T. Eric Layton

I was studying ahead for this next week's CCNA class stuff this weekend. I was having a hard time wrapping my head around subnetting, though, so I set aside Sunday to conquer this topic. I was determined to learn this if it took all day. Subnetting questions are a BIG part of the CCNA test. Well, turns out it nearly did take the entire day. If you're interested in subnetting and subnet masking, here are the fruits of my labors from yesterday...

 

Subnet Masking Notes - Self Study Sunday 20 Jan 2013

 

This is a compilation of notes on subnet masking using Richard Deal's method, Wendell Odom's method, and my own hybrid method along with some practice examples.

 

1) Determine the network and host requirements

 

- determine the number of hosts needed for the largest subnet.

 

- determine the maximum segments (subnets) that you have in the network... how many subnets will be needed, in other words.

 

If dealing with an existing network, in depth analysis will be necessary to determine the above requirements.

 

If designing a new network, you will most likely already have mapped out your needs.

 

You will also need to know the network IP (ID) and determine the class of IP (A, B, C, etc.)

 

2) Satisfy host and network requirements

 

2 sub S = number of networks you need (S represents subnet bits)

 

2 sub H - 2 = number of useable hosts (two reserved for subnet and b-cast addresses) on your largest sedment (H represents host bits)

 

S + H = total number or host bits you have for a class of address*

 

*A = 24, B = 16, C = 8

 

3) Determine the subnet mask

 

Note: This section of Deal's method is confusing to me. Leaving blank for the moment. (see first exercise step 3 below for details on how to accomplish this step)

 

4) Determine the Network Addresses

 

Each network address increments above the zero subnet by a factor equal to the 2 sub S above. For instance, if the above was 2 sub 4, the increment between subnets would be 16. If 192.168.1.0 were the zero subnet, then the next subnet would be 192.168.1.16, next 192.168.1.32, next 192.168.1.48, etc.

 

5) Determine the Directed Broadcast Addresses (b-cast) of each Subnet

 

Simple subtract 1 from the next subnet to give you the b-cast of the current subnet. Using the subnets above in step 4, for example, you'd have subnet 192.168.1.16 --> b-cast = 192.168.1.31, subnet 192.168.1.32 --> b-cast = 192.168.1.47, etc.

 

6) Determine the Hosts Addresses

 

- the host address ranges would simply be the range between subnet and the broadcast IP. For instance, if the subnet was 192.168.1.0 and the b-cast was 192.168.1.15, the range of usable host address would be 192.168.1.1 to 192.168.1.14... and so on for each subnet.

 

Easy-peasy, right?

 

OK, here are some exercises to test how this works...

 

Exercise ONE:

 

Step 1

 

You have a Class C network (192.168.1.0). You need 4 segments (subnets) and 50 hosts/segment. Find the subnet mask, the subnets, the direct b-casts, and the host ranges.

 

Step 2

 

> 2 sub S = number of subnets

- in this case we need 4 subnets, so 2 sub 2 = 4

- S (network bits) = 2

 

> 2 sub H - 2 = number of hosts

- we need 50 hosts in this case, so 2 sub 6 = 64 hosts will work for us

- H (host bits) = 6

 

> S + H = Class host bits - in this case, Class C

- 2 + 6 = 8

 

Step 3

 

Using Deal's rather confusing method in step 3 of his book, I can determine that the subnet mask of this network ID (192.168.1.0) will be 255.255.255.192.

 

Here's how I broke down the mask:

 

| network bits = 24* | subnet bits (H) = 2 | host bits (S) = 6 |

 

*remember Class C

 

Add class address network bits to subnet bits: 24 + 2 = 26

 

Using DDN (dotted decimal notation) to create the mask, we know that Class C addresses have the the first three octets as the network address, so the first three octets of the mask are all 1s --> 255.255.255.?

 

Since we know used 6 host bits from our calculation in Step 2, we can determine that the host number in the mask will be the addition of the 6 least significant figures in that byte --> 32+16+8+4+2+1 = 63. Now subtract 63 from the full byte (255) and that comes to 192.

 

OR (easier method using binary)

 

First 24 network bits = 11111111.11111111.11111111.x

 

Remaining subnet bits = 11000000 = 192 decimal

 

So, the subnet mask for 192.168.1.0 is 255.255.255.192 or 192.168.1.0/26 (Prefix or CIDR - classless interdomain routing)

 

Steps 4, 5, and 6 in a charted format:

 

subnet hosts b-cast

192.168.1.0 192.168.1.1 to 192.168.1.62 192.168.1.63

192.168.1.64 192.168.1.65 to 192.168.1.126 192.168.1.127

192.168.1.128 192.168.1.129 to 192.168.1.190 192.168.1.191

192.168.1.192 192.168.1.193 to 192.168.1.254 192.168.1.255

 

Here's where I had problems...

 

Exercise TWO:

 

Step 1

 

You have a Class B network (172.16.0.0). You need 490 segments (subnets) and 112 hosts/segment. Find the subnet mask, subnets, direct b-casts, and host ranges.

 

Step 2

 

> 2 sub S = number of subnets

- in this case we need 490 subnets, so 2 sub 9 = 512

- S (network bits) = 9

 

> 2 sub H - 2 = number of hosts

- we need 112 hosts in this case, so 2 sub 7 = 128 hosts will work for us

- H (host bits) = 7

 

> S + H = Class host bits - in this case, Class B

- 9 + 7 = 16

 

Step 3

 

| network bits = 16 | subnet bits (S) = 9 | host bits (H) = 7 |

 

network + subnet bits = 25 --> /25 CIDR

 

First 16 network bits = 11111111.11111111.x.x

 

Remaining 9 subnet bits --> 11111111.1000000

 

Subnet mask for 172.16.0.0 - 255.255.255.128 or 172.16.0.0/25

 

Steps 4, 5, and 6 in charted format

 

subnet host b-cast

172.16.0.0 172.16.0.1 to 172.16.0.126 172.16.0.127

172.16.0.128 172.16.0.129 to 172.16.0.253 172.16.0.254.

172.16.1.0 172.16.1.1 to 172.16.1.126 172.16.1.127

172.16.1.128 172.16.2.129 to 172.16.1.253 172.16.1.255

 

and so on for 508 more subnets.

 

One last one...

 

Exercise THREE:

 

Step 1

 

You have a Class A network (10.0.0.0). You need 9000 segments (subnets) and 560 hosts/segment. Find the subnet mask, subnets, direct b-casts, and host ranges.

 

Step 2

 

> 2 sub S = number of subnets

- in this case we need 9000 subnets, so 2 sub 14 = 16,384

- S (network bits) = 9

 

> 2 sub H - 2 = number of hosts

- we need 560 hosts in this case, so 2 sub 10 = 1,024 hosts will work for us

- H (host bits) = 10

 

> S + H = Class host bits - in this case, Class A

- 14 + 10 = 24

 

Step 3

 

| network bits = 8 | subnet bits (H) = 14 | host bits (S) = 10 |

 

network + subnet bits = 22 --> /22 CIDR

 

First 8 network bits (Class A) = 1111111.x.x.x

 

Remaining 14 subnet bits - 1111111.11111100.0000000

 

Subnet mask = 10.0.0.0 - 255.255.252.0 or 10.0.0.0/22

 

This would give you 16,284 subnets (10.0.0.0, 10.0.4.0, 10.0.8.0, etc.) each with 1024 addresses of which 1022 are usable for host devices (0 and 255 reserved, as always).

 

=====

 

I've found that using the binary network+subnet bits method in Step 3 is the easiest way for me to determine that "interesting octet" (the non-255 octet), particularly on the class B and C exercises.

 

OK, I had to use a hybrid of Deal's and Odoms methods before I could wrap my head around how this works. Now I just need to practice, practice, practice!

 

=====

 

6 Steps for Determining IP Address Components

 

1. You know an IP and a subnet mask

 

- you want to determine if the IP is a network, host, or broadcast IP

 

- REMEMBER: network IPs are always even numbers (last octet), broadcast IPs are always odd numbers, host IPs can be either

 

2. Look at the subnet mask and find the "interesting octet"... the octet that is the border between the network and host.

 

- it will always be one of these - 0, 128, 192, 224, 240, 248, 252, and 254

 

- only when an octet contains one or more binary zeros is it a host component

 

3. Subtract the interesting octet from 256 -->

 

- 256 - interesting octet = increment number (magic number)

 

4. Create a subnet chart starting at "subnet zero" - xxx.xxx.xxx.0 - incrementing by your "magic number" and work your way up to just past the subnet that contains the IP from #1 above.

 

5. After you've created your partial chart for the subnets, add the b-casts to the chart.

 

- REMEMBER, b-cast address is always one less than the next subnet address --> b-cast = next subnet address - 1

 

6. Between your subnet addresses and the b-casts on your partial chart, fill in the hosts ranges for each subnet.

 

- the hosts range will be all available IPs between the subnet address and the b-cast address.

 

Let's do an exercise to see how this works. We'll "reverse engineer" one of our exercises above to illustrate better the processes involved.

 

Exercise ONE:

 

1. We know the IP is 192.168.1.134 and the subnet mask is 255.255.255.192 or 192.168.1.0/26.

 

So...

 

2. Determine the interesting octet, the boundary between network and host. In this case it's the last one on this mask - 192.

 

- REMEMBER, only octets that contain one or more binary zeros will have a host component --> 192 = 11000000 binary = host portion of mask

 

3. Using our formula for determining the magic (incremental) number --> 256 - interesting octet = magic number (subnet increment) -- 256 -192 =64, so we now know that our subnets on this network increment in steps of 64.

 

4. Now that we know our increment number and our subnet zero IP, we can begin to make our chart:

 

subnet

 

192.168.1.0

192.168.1.64

192.168.1.128

192.168.1.192

 

5. From the above subnet chart we can determine the b-cast addresses for each subnet:

 

- REMEMBER, b-cast addys are always 1 less than the next subnet addy

 

subnet hosts b-cast

 

192.168.1.0 192.168.1.63

192.168.1.64 192.168.1.127

192.168.1.128 192.168.1.191

192.168.1.192 192.168.1.255*

 

*you don't have another subnet to subtract the -1 from to determine this last b-cast, but you do know that 255 is the highest value you can have in a single byte (octet) of an IP. Also, incrementing the last subnet by 64 would give you 192.168.1.256, which tells you right there that this network only has 4 segments (subnets) total because 256 is not a valid value for that last octet.

 

6. You can now fill in your host ranges. For brevity's sake, I'm only going to show the range that contains the IP we are investigating:

 

subnet hosts b-cast

192.168.1.128 192.168.1.127 to 192.168.1.190 192.168.1.191

 

From the above you can see that our mystery IP of 192.168.1.134 belongs to the 192.168.1.128 subnet and it is indeed a host address.

 

Here's a tricky one...

 

Exercise TWO:

 

1. You have an IP of 172.16.5.0 with a subnet mask of 255.255.254.0

 

- first off, note that this is a Class B address

 

2. Find the interesting octet - the boundary between network and host

 

- this is a Class B address. REMEMBER, Class B addresses = network-16 bits (first two octets), host-16 bits (last two octets)

 

So, in this case our interesting octet is the third one - xxx.xxx.254.x

 

3. Using this, we can determine the increment number that the subnets will increase in this network by pluging the numbers into our formula --> 256 - interesting octet (254) = 2 --> the subnets will increment by 2 (in the THIRD OCTET - network host boudary in this Class B address)

 

4. Build your network chart:

 

subnets

 

172.16.0.0 (subnet zero)

172.16.2.0

172.16.4.0 --> we can already see that our mystery IP will be in this subnet somewhere

172.16.6.0

 

5. Add your b-cast addresses:

 

subnets b-casts

--- ---

--- ---

172.16.4.0 172.16.5.255*

172.16.6.0 172.16.7.255*

----

 

*b-cast always one less (-1) than next subnet

 

6. Add your host ranges:

 

subnets hosts b-casts

--- --- ---

--- --- ---

172.16.4.0 172.16.4.1 to 172.16.5.254 172.16.5.255

172.16.6.0 172.16.6.1 to 172.16.7.254 172.16.7.255

--- --- ---

 

At first glance of the mystery IP, one would almost think that it was a subnet address. This is what made this one tricky. 172.16.5.0 actually falls into the range of hosts addresses on the 172.16.4.0 subnet.

 

Note: for test-taking purposes, you don't have to build the entire chart. Just zero in on the subnet that you know contains the address you're investigating. Figure out where that address fits into that subnet... is it the subnet address, a host, or a b-cast addy? REMEMBER, subnets = even number (last octet), hosts can be either even or odd, b-cast = odd number.

 

So, there you have it.

 

=====

 

End today's notes.

 

Looks like fun stuff, huh? ;)

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V.T. Eric Layton

OK, studied bunches and bunches the past three days. I've built my confidence level back up a bit. Sadly, as I shove new stuff in, I think some of the older learned stuff is leaking out. I did worse on some assessment exams tonight than I did originally a week or so ago. RUH-ROH! Brain reaching capacity? Buffers overloaded? Oh noes....

 

Time to take a break. I finally (Saturday) was able to pick up Inspector Lewis Season 2 that I had reserved at the library months ago. Figures it would come in now that I'm too busy to watch them. I'm going to go watch a couple right now, though. I need some pleasant distraction from all this studying. I'm starting to dream about this stuff.

 

Off I go...

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Inspector Lewis - cool! Do you like Morse as well? I love most of the English cop shows like that, especially Midsomer Murders, also Waking The Dead and Spooks.

 

BTW, was your previous post written in Klingon? It was all Greek to me. :D

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Guest LilBambi

Good one sunrat!

 

Yes, time to air out the brain with some well deserved entertainment. And don't forget some exercise. They say the real brain clearer is exercise. Bet you haven't had time to ride your bicycle.

Edited by LilBambi
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V.T. Eric Layton

Inspector Lewis - cool! Do you like Morse as well?

 

Morse is my absolute favorite! I really like Lewis and Hathaway, but Morse was DA' MAN!

 

I also LOVE the Barrington Pheloung theme song for Morse...

 

 

 

BTW, was your previous post written in Klingon? It was all Greek to me. :D

 

Uh... it's Network-speak. ;)

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V.T. Eric Layton

Good one sunrat!

 

Yes, time to air out the brain with some well deserved entertainment. And don't forget some exercise. They say the real brain clearer is exercise. Bet you haven't had time to ride your bicycle.

 

I'm working out every morning with two 35 lbs dumb bells that I inherited from my nephew Jason who passed away in 2009. My goal is to have Pauly Sr. arms by this summer.

 

Paul-Sr.jpg

 

Without the tattoos, though. For those who don't know... Pauly Sr. is founder/owner of Orange County Choppers.

 

I haven't had the chance to walk or ride my bike much this past three weeks. :(

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V.T. Eric Layton

Our class for today is meeting at the Dale Mabry campus so we can tour the networking room over there. This campus is literally walking distance from my house... about 1 mile. However, I don't feel like carrying the 10 lb text book and my 25 lb laptop bag that far, so I'll drive over there. ;)

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Our class for today is meeting at the Dale Mabry campus so we can tour the networking room over there. This campus is literally walking distance from my house... about 1 mile. However, I don't feel like carrying the 10 lb text book and my 25 lb laptop bag that far, so I'll drive over there. ;)

I always miss you when you are around. I am on that campus every Monday and Wednesday. You go on a field trip on Tuesday. Figures!

I could have bought you a salad.

Edited by amenditman
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V.T. Eric Layton

I had a cup of some nasty dark roast coffee in the cafeteria over there today. Man! There is some nice scenery on that campus.... young, though. :yes:

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Even the older students in my classes (around 30) make me realize how young, idealistic, and unrealistic they are.

 

There are a few of us who qualify as experienced and gaining wisdom, but we are few.

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V.T. Eric Layton

I removed this method of subnet analysis because I found that it was faulty. I'm still having trouble grasping this simple concept. It's starting to deteriorate my confidence. The ability to subnet and analyze existing subnets is a BIG part of this certification exam.

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I removed this method of subnet analysis because I found that it was faulty. I'm still having trouble grasping this simple concept. It's starting to deteriorate my confidence. The ability to subnet and analyze existing subnets is a BIG part of this certification exam.

 

You need to chill man. Relax and watch some movies.

 

http://www.savevid.com/video/subnetting-in-6-easy-steps-part-1flv.html

 

How to do TCP/IP Subnetting in your head. All you have to do is remember 6 questions

 

http://www.savevid.com/search?q=+Subnet+Analysis%2C+Part+&c=1

 

Could not find part one.

 

Anyways waht you waiting for ? Go get the popcorn and chill with the above movies. :breakfast:

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Don't worry Eric,

 

I've had several people try to explain to me how to calculate a subnet. All have failed. I think there is a principle at work that most people accept that I am not aware of- and this seems to be the stumbling block. Once I figure it out, subnetting will make perfect sense to me.

 

For what it's worth- have you tried sitting down with your instructor and discussing the topic? Maybe you could go through it a couple times and he/she could point something out to you in order to help.

 

Adam

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V.T. Eric Layton

Oh, I have it now.

 

I was told by a few networking dudes that learning subnetting takes five stages (like the stages of grief ;) ):

 

1) Total mindblowing incomprehension

 

2) A partial understanding, but still getting it wrong

 

3) Frustration with your stupid head and its inability to understand simple arithmatic

 

4) The EPIPHANY moment when you realize what you were missing

 

and finally

 

5) Understanding and kicking one's self in rear area for being so thick headed in the first place

 

That's about how it went for me. Now the trick is increase my speed. That just takes practice, practice, and more practice. I've been doing 15-25 subnetting questions a day for the past few days. It's helping with the speed thing. :yes:

 

-------

 

As far as the rest of the CCNA thing goes... we're just a week or so away from our first examination - ICND1 (for those who are going the 2-test route). The sample tests I've been taking are telling me that there's a WHOLE LOT that I still need to digest in just a short period of time. The confidence level (read as cockiness) of my classmates and myself has diminished greatly since the first week of class. We're making inroads to understanding, though.

 

I look at it this way:

 

Even if I wash out and fail the test, I'll be MUCH more prepared for it the next time. Also, I've learned tons of carp about networking that I had always been interested in, but was too lazy to pursue. I could probably pass the CompTIA Network+ test and the A+ with no tribbles at all thanks to this cram CCNA course and my prior hardware knowledge. I intend to take them soon, also... even if they're not too valued by industry anymore.

 

This theory knowledge and certifications with the accompanying alphabet soup after your name are just a means to an end. They're your passport to better job opportunities and higher pay. They're not something that you will be using daily on-the-job once you actually have that job. I learned that in my electronic career. I learned hours and hours of physics, electronics, engineering principles, advance mathematics, etc. to gain my degree. However, not once in my entire career in electronics did I whip out my Texas Instruments TI-30 calculator to figure current flow through a circuit. I just used a meter to check it. ;)

 

TI-30

 

220px-TI-30_LED.png

 

I'm wasting study time here. :(

 

Later...

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V.T. Eric Layton

Go for it, Adam. It just takes time. The books (many, many of them) are available used online for a pittance. If you're disciplined enough for self-study, you'll be able to learn a heck of a lot just reading through a book or two. You'll have to buckle down to some more intense study to pass the tests, though. Cisco tests require more than rote memorization, as with the some other cert tests. With Cisco, you better have an understanding of how something, like TCP/IP works, not just know it's acronym. ;)

 

OK, my break from studying is just about over. I just finished two detailed chapters on TCP/IP, involving the actual run up and down the TCP/IP stack from signal to application and back down to signal, along with all the devices involved and what they needed to do for everything to work properly. It's actually pretty darned amazing how this is done.

 

I'm now off to use my Cisco SIM app to troubleshoot a WAN that I designed and implemented last night (homework). I have one leg of the WAN (the factory) that isn't able to communicate with the home office or the warehouse. Can't have that. The boss is not happy. It should be an easy fix. I have it narrowed down to a mis-configured router.

 

Here's what it looks like, if you're interested...

 

th_sim-07_week-4_lab-ver2_zps92005751.jpg

 

Later...

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I am working on my Bachelor's degree right now (A generic Tech Management one) and am taking a break due to the birth of the formula-slurper. :) Once I get back into school, it will take my time up again. One of my next classes is project management, which will require me to become familiar with Microsoft Schedule +. That means I need to have an installation of Windows 7 around here that I can use. Lucky me- I don't have a PC strong enough to do it, so I will be dual booting my Mac. This is something I never thought I would be doing, but I do have plenty of space on the SSD to run WIndows, so I should have a very fast OS to play with.

 

Ain't technology grand?

 

Adam

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V.T. Eric Layton

I hope MS Schedule + is an improvement over MS Project. I HATED that latter app. I had to learn it back in '92 when I was p-managing for my brother on a 400 home dev here in the Tampa area. I did not like MS Project at all. I ended up trashing it and using Timberline (by Sage) instead.

 

There's only so much time in the day to learn all we want to learn. Have fun learning what you can. :yes:

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V.T. Eric Layton

OK, it was a bad weekend (sick kitty). I totally was not able to concentrate at all on my studies. MUST knuckle down NOW!

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