Subnetting
- Thread starter Nate G
- Start date
I show in Courses this Video.
Not to long. Understandable.
Enough for Subnetting /24 in smaller Subnets. In Real Life you just use any Subnet Calculator out there.
I never figured out what he does in his Video Professor Messer - Seven Second Subnetting;
Michael
Not to long. Understandable.
Enough for Subnetting /24 in smaller Subnets. In Real Life you just use any Subnet Calculator out there.
I never figured out what he does in his Video Professor Messer - Seven Second Subnetting;
Michael
Well, the methods I've used and taught are these:
1) Magic Number - - This is basically the Cisco method to subnetting. I've found this to be the easiest and fastest method for subnetting.
2) Power of Two - Requires math, bit borrowing, and conversion within the octet (or a bit more brainpower if you're Supernetting)
3) Binary Math - If you have a thing for pain, love taking four times as long to do something, or can actually do it this way, you can just add or subtract through the subnet mask to give your answer.
Professor Messer's builds two large tables so all he has to do is lookup the values. This is a variant of Magic Number. For me, I just build a table like this. Messer's table is more elaborate, so that it covers all CIDR from /1 to /32, but it's basically the same process. It might take seven seconds to do a lookup on those tables, but it will cost the candidate time writing out the table on the slate/paper.
Magic number is really the best way for calculating those questions like:
You have the address of 204.71.82.91/28.
What is the Network ID
What is the Broadcast ID
How Many hosts are in the subnet.
I'll let someone else chime in with the calculation. And tell me what method you used, particularly if I didn't mention it here.
/r
1) Magic Number - - This is basically the Cisco method to subnetting. I've found this to be the easiest and fastest method for subnetting.
2) Power of Two - Requires math, bit borrowing, and conversion within the octet (or a bit more brainpower if you're Supernetting)
3) Binary Math - If you have a thing for pain, love taking four times as long to do something, or can actually do it this way, you can just add or subtract through the subnet mask to give your answer.
Professor Messer's builds two large tables so all he has to do is lookup the values. This is a variant of Magic Number. For me, I just build a table like this. Messer's table is more elaborate, so that it covers all CIDR from /1 to /32, but it's basically the same process. It might take seven seconds to do a lookup on those tables, but it will cost the candidate time writing out the table on the slate/paper.
| CIDR | /24 | /25 | /26 | /27 | /28 | /29 | /30 | /31 | |
| No. Networks | 1 | 2 | 4 | 8 | 16 | 32 | 64 | 128 | |
| No. Hosts | 254 | 126 | 62 | 30 | 14 | 6 | 2 | 1 |
Magic number is really the best way for calculating those questions like:
You have the address of 204.71.82.91/28.
What is the Network ID
What is the Broadcast ID
How Many hosts are in the subnet.
I'll let someone else chime in with the calculation. And tell me what method you used, particularly if I didn't mention it here.
/r
We use a subnetting workbook.
A similar document can be download from this link: Click here
We usually have our print department produce the said documents, so our students can manually write onto the printed copy. You may also consider printing a few copies for your students.
I hope this helps!
A similar document can be download from this link: Click here
We usually have our print department produce the said documents, so our students can manually write onto the printed copy. You may also consider printing a few copies for your students.
I hope this helps!
AA fun oldy but goodie from cisco
I can dig up some more, if I know what you are looking for.
[email protected]
I can dig up some more, if I know what you are looking for.
[email protected]
That
.
.
was
.
.
painful.
Networking has no business as part of a Saturday morning style cartoon. No. Just no. *smh*
/r
.
.
was
.
.
painful.
Networking has no business as part of a Saturday morning style cartoon. No. Just no. *smh*
/r
I actually like Peter Packet. It is intended to be a kid-oriented learning module.
See link for reference: http://www.allandye.com/peter.html
However, for adult learners, I don't think Peter Packet would be an ideal resource.
See link for reference: http://www.allandye.com/peter.html
However, for adult learners, I don't think Peter Packet would be an ideal resource.
In it's time Peter Packet was important. Based on my recent experience interacting with youth seeking CCNA and Security+ I'd say it may be important again now. The reason being that too many students don't have a good (or any?) foundation in math (other than addition and subtraction). Subnetting is hard if all the student understands is base 10 math. They have to learn a lot. Binary math. Octal math. Dotted decimal notation. I'm guilty of standing in front of students and saying that practicing professionals use subnet calculators. I don't do that anymore because I've seen and heard from some practicing professionals about really basic errors that they would have (should have) caught if they hadn't relied on that subnet calculator.
So now this opens up a new area of discussion - prerequisite skills needed to accomplish professional grade tasks. I would totally agree, Brian, that students at the secondary level do not have a decent grasp of technical mathematics - heck, most students struggle with basic finite math as a college freshman when they should be looking at more applicative math.
<soapbox>
From a general perspective, this is a general failure of the architecture of the education system - we're still teaching students using the Renaissance model, rather than teaching according to vocational/professional proficiency. We plague students with unnecessary coursework that is irrelevant to what they will professionally do and don't guide them into the relevant coursework that will form the functional basis of their vocation. Or does anyone really want to justify courses like Geology and Art and Music Appreciation to someone who is going into Networking, Cybersecurity, or Cloud Services Administration.
We don't train students to *do*. We just throw them a bunch of classes in cookie cutter fashion. So students don't see that coursework like technical algebra is valuable, but Trigonometry is not, unless you're going to get into power systems design as a EE/EET.
</soapbox>
I have always had a difficult time with cartoon style training because it always feels forced and out of context to me. I'm sure the creators of Peter Packet may think or feel differently, but I've never found that kind of thing valuable. I learned subnetting by actually subnetting a real or virtual environment. I'm pretty sure my position here is unpopular, but...well, that's me.
I do know there has been a growing push for edu-tainment and gamification of learning, because of this sense that we "have to make it fun for them to learn". But the way I see it, if we have to resort to gimmicky training styles, how engaged are the students, really?
Learning is the exclusive domain of the student.
/r
Hey @Jarrel, I use the same workbook to help those students who really want to understand and own the knowledge behind IP addresses. I also have the 2.0 versions of both the Instructor and Student. If your interested in having those reach out to me here and I'll get them uploaded to you.
Hey Rick, here is one of the PowerPoints that we have that delves a bit deeper that that of Messer's table. A colleague of mine created it and I updated it to the current version when we're teaching Classless Inter-Domain Routing (CIDR).
But another topic that I'd like to extend to this one is that it's all nice till you require more than 254 hosts, and how that impacts our IP address ranges. True this isn't what they would need to know for the certification exam, but what abot when they encounter this situation with a real world/job requirments. Let me guess, IP Calculator? Personally I tell my students that I "Trust but verify" everything so then need to know how to confirm those calculations. I'll provide in another replay a copy of a table that I use to help them with this. Be advised: It may not make sense without some explaination
Here is a copy of the table that I use to help them understand when we go beyond the typical requirement for 126-254 available hosts on a Internal/Private Network. Again I'll reinerate that it may not intially make sense with some explanation. And if someone would need that, then please feel free to hit me up here and perhaps we can schedule a time to accomplish this one-on-one. Otherwise I'll leave it to you.
