[SOLVED] Noob to Classless Ip addressing

superd123 · 03-14-2008, 08:46 AM

I was just wondering whether someone could help me subnet this network.

For my coursework I am trying to develop a network and give it subnets. I'm also going to use Classless IP addressing.

The only problem Im just a complete noob at it.

If someone help me with this, It would be great.

I am to use the Ip address 172.10.2.0/21 The original campus at Windsor is developing a new site at Slough with 10 Buildings. Each Floor will have a max. of 30 hosts.

Here are the buildings:

Building 1= 4 Floors
Building 2 = 3 Floors
Building 3 = 3 Floors
Building 4 = 2 Floors
Building 5 = 4 Floors
Building 6 = 3 Floors
Building 7 = 4 Floors
Building 8 = 3 Floors
Building 9 = 3 Floors
Building 10 = 3 Floors

My tutors says developing a classless Ip addressing scheme will take 5 mins, I just dont have a clue where to start!!

Please Help!!

Thanks,
Darren

**Cellus** · 03-14-2008, 07:54 PM

I'm sorry but it is against our Rules to directly assist with classwork (assignments, homework, etc).

I can however tell you this. A classless IP addressing scheme (aka. Classless Inter-Domain Routing, or CIDR) is a scheme that does not restrict itself to the traditional class-based scheme (ie. Class A, Class B, Class C, etc.), and is used primarily to create subnets within a pre-existing subnet. For starters, lay out the subnet you have given to you onto a piece of paper in binary (Base2), separating every eight bits (one byte, or octet). This should leave you with a long string of converted binary with four chunks. Need to find out how many bits you have to play with? Well the address that was given to you has a mask of 21 bits (as shown with the /21). Starting from the right, count left 21 bits and draw a big line down the page. Everything to the right of the line will be the bits you can play with (can be manipulated and broken down into subnets and hosts, etc). Everything to the left of the line is firmly a part of your network and can not be changed.

I'll leave the rest of the work to you. If you are unsure how to do the rest, I highly recommend you approach your tutor. I will however give you an important reminder/hint: remember to subtract two (2) from your host count when forming a subnet. The first host address in the subnet is reserved for the network (the IP which represents the new subnet), while the last host address in the subnet is reserved for broadcast (the IP used to broadcast within that new subnet).

superd123 · 03-15-2008, 02:31 AM

Im sorry, i didn't realise that but i appreciate your help nonetheless.

**Cellus** · 03-18-2008, 12:56 PM

No problem.

03-14-2008, 08:46 AM	#1 (permalink)
superd123 Registered User Join Date: Mar 2008 Posts: 2 OS: Windows XP	[SOLVED] Noob to Classless Ip addressing I was just wondering whether someone could help me subnet this network. For my coursework I am trying to develop a network and give it subnets. I'm also going to use Classless IP addressing. The only problem Im just a complete noob at it. If someone help me with this, It would be great. I am to use the Ip address 172.10.2.0/21 The original campus at Windsor is developing a new site at Slough with 10 Buildings. Each Floor will have a max. of 30 hosts. Here are the buildings: Building 1= 4 Floors Building 2 = 3 Floors Building 3 = 3 Floors Building 4 = 2 Floors Building 5 = 4 Floors Building 6 = 3 Floors Building 7 = 4 Floors Building 8 = 3 Floors Building 9 = 3 Floors Building 10 = 3 Floors My tutors says developing a classless Ip addressing scheme will take 5 mins, I just dont have a clue where to start!! Please Help!! Thanks, Darren

03-14-2008, 07:54 PM	#2 (permalink)
Cellus Moderator Networking Team Join Date: Aug 2006 Location: Canada Posts: 2,526 OS: Windows Vista Business SP1, Windows XP Professional SP3 My System	Re: Noob to Classless Ip addressing I'm sorry but it is against our Rules to directly assist with classwork (assignments, homework, etc). I can however tell you this. A classless IP addressing scheme (aka. Classless Inter-Domain Routing, or CIDR) is a scheme that does not restrict itself to the traditional class-based scheme (ie. Class A, Class B, Class C, etc.), and is used primarily to create subnets within a pre-existing subnet. For starters, lay out the subnet you have given to you onto a piece of paper in binary (Base2), separating every eight bits (one byte, or octet). This should leave you with a long string of converted binary with four chunks. Need to find out how many bits you have to play with? Well the address that was given to you has a mask of 21 bits (as shown with the /21). Starting from the right, count left 21 bits and draw a big line down the page. Everything to the right of the line will be the bits you can play with (can be manipulated and broken down into subnets and hosts, etc). Everything to the left of the line is firmly a part of your network and can not be changed. I'll leave the rest of the work to you. If you are unsure how to do the rest, I highly recommend you approach your tutor. I will however give you an important reminder/hint: remember to subtract two (2) from your host count when forming a subnet. The first host address in the subnet is reserved for the network (the IP which represents the new subnet), while the last host address in the subnet is reserved for broadcast (the IP used to broadcast within that new subnet). __________________ TSF Networking Team HijackThis 5 Step Process Donate! Last edited by Cellus : 03-14-2008 at 07:59 PM. Reason: refined

03-15-2008, 02:31 AM	#3 (permalink)
superd123 Registered User Join Date: Mar 2008 Posts: 2 OS: Windows XP	Re: Noob to Classless Ip addressing Im sorry, i didn't realise that but i appreciate your help nonetheless.

03-18-2008, 12:56 PM	#4 (permalink)
Cellus Moderator Networking Team Join Date: Aug 2006 Location: Canada Posts: 2,526 OS: Windows Vista Business SP1, Windows XP Professional SP3 My System	Re: Noob to Classless Ip addressing No problem. __________________ TSF Networking Team HijackThis 5 Step Process Donate!