I've soo very much forgotten all of this. Sorry! xD
let's ask dwdanne.

/r/ DWDANNE

I learned subnetting 6 months ago, and forgot it all.

Why was subnetting not done automatically? Stupid.

*waits for IPv6*

You didn't learn subnetting, and you don't seem to understand the first thing about it.

Actually I did learn subnetting.

CETY - Course Code / 3yr
Centennial College
Networking Introduction - Lecture Class
Semester 2

Yeah.

that didn't make you look cool btw

I know, there's nothing cool about what I do.

=(

That's not even a supernet. The 172.16.0.0/12 private address space is a /12, but, of course, the netblock itself is a class-B classical address. You are subnetting 3 bits.

It depends entirely on what you're doing whether it will "affect other networks." If you're only going to use the 172.27.96.0 network, then you should be fine. However, if you are going to make use of any other networks in the mask, then you can have address conflicts. For instance, this configuration allows for the subnets 172.27.32.0/19 and 172.27.64.0/19. You have 2^3 or 8 subnets available with this mask, and 8192 - 2 hosts per network, assuming you zero subnet.

I forgot to mention routing as well. I doubt you are doing any routing, less any serious routing, but, if you are, then of course things can be affected depending upon what routes you advertise and what routes you put in static tables. That's a little too broad a category to get into without knowing more information, however. But, of course, if you advertise more specific prefixes, then those routes will be preferred by devices in your network.

I'd also like to mention that I don't know if you really understand classes that well. I didn't really catch this when I first read your post, but it seems that you think somehow a network spanning the first three octets necessarily constitutes a class-C. It does not. Classes are based upon the first four bits (MSB first) of the first octet of an IPv4 address.

Good info, we're learning subnetting now in my networking class.

To add to that the network listed above would be a class B, not C. Sounds like he confused the two, I'm not positive on his thinking though.

A = First octet 1 - 126
B = First octet 128 - 191
C = First octet 192 - 224

...just incase.

Yes so i have a class b network, which i've chosen to subnet into many class C's what i want is to mix C with a supernet for ~8000 hosts.
So
172.27.2-80 as networks /24
then add a network which has 8000~ hosts spanned over 30~ subnets

172.27.96.0 /19 (255.255.224.0)

So the question is, does the above network conflict with 172.27.80.0 and 172.27.200.0

Haven't I already answered your question? And 172.27.96.0/19 is not a supernet. 172.27.96.0 is a class-B address, which masks the first 16 bits of an IP address. 19-16 = 3 bits of subnet. A supernet would be something like 172.27.0.0/15.

Again, it depends on what you mean by conflict and which subnets you'll be using (and whether you're routing them).
If you are only using the 96 subnet and you are not doing any routing, then there should be no problem. There is nothing inherent about a network which makes it somehow "conflict" with another network.
A subnet mask is not even a tangible thing that is passed along in normal network communications. It is a filter applied by the host computer to communications it sends and receives.

In certain cases, networks with different subnet masks can still communicate directly over ARP (without routing). On the network I'm using now, for instance, my adapter's configured to the 192.168.1.0/25 network. Yet I still have static routes in place for a /24, which includes that network, so there is no issue in accessing one from the other.

If you wish to have interaccessibility between your networks, then you will have to route between them. This can be achieved by using a very un-specific route (e.g. 172.27.0.0/16), if you wish to do that. But there should be no direct address conflicts if you only peruse of the 96 subnet. This table probably won't work:

172 . 27 . 96 . 0

10101100 . 00011011 . 01100000 . 00000000

255 . 255 . 224 . 0

11111111 . 11111111 . 11100000 . 000000000


subnet network (binary) network(dotted quad)

1 10101100 . 00011011 . 00000000 . 00000000 172.27.0.0/19 (zero-subnet)
2 10101100 . 00011011 . 00100000 . 00000000 172.27.32.0/19
3 10101100 . 00011011 . 01000000 . 00000000 172.27.64.0/19
4 10101100 . 00011011 . 01100000 . 00000000 172.27.96.0/19
5 10101100 . 00011011 . 10000000 . 00000000 172.27.128.0/19
6 10101100 . 00011011 . 10100000 . 00000000 172.27.160.0/19
7 10101100 . 00011011 . 11000000 . 00000000 172.27.192.0/19
8 10101100 . 00011011 . 11100000 . 00000000 172.27.224.0/19 (zero-subnet)

But maybe you can paste it into a text editor. You can see that there are 8 subnets available using this subnet mask, if you allow zero-subnetting (1 2).
And you can see that two of the available subnets (172.27.32.0/19 and 172.27.64.0/19) would conflict with your class-C subnets.

Kdawg, I bet you can setup a print server like no man.

There is also a very good subnetting tutorial available here if anyone wishes to read it.

No.

wow, some geeky ass shit ;p

Backstreet Boys

Sorry, but I've forgotten almost everything I learned when getting my CCNA. :(