RE: Addressing Scheme

Unanswered Question
Mar 18th, 2008

Guys,

Please help!!!

I have been asked to design an addressing scheme that will support 930 users. The design must allow for 30% growth, so if my calculations are correct this would take us to 1209.

Glasgow Office:

50 Warehouse Staff

150 Customer services

100 Finance

Total 300 (still to add 30%)

Birmingham office

75 Warehouse staff

100 Customer services

75 Finance

Total: 250 (still to add 30%)

Five regional sites

Aberdeen 20 staff

Newcastle 40 staff

Liverpool 20

Bristol 20

london 30 staff

Total 250 (still to add 30%

each region also has a number (up to 5) of smaller branch sites with less than 10 staff each.

The company leases a range of class C networks of public IP addresses from its main ISP.

I am trying to find a suitable Network address that will support this.

Many thanks

Scott

I have this problem too.
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Danilo Dy Tue, 03/18/2008 - 04:47

Hi,

Did they give you a range of IP Address to use and subnet?

If not, this means you have a free hand on the ip address assignment. Use some coding in the second and third octet to identify the site and department.

Regards,

Dandy

scott_mchale Tue, 03/18/2008 - 04:51

Hi Dandy,

No range of IP addresses or subnets given.

Not sure what you mean by "coding in the second and third octet to identify the site and department."

Seem to be hitting a wall everytime when using VLSM.

what Network Address should I use.

Regards

Scott

scott_mchale Tue, 03/18/2008 - 04:57

Hi Dandy

Cant see your reply, even though I received an email to advise one had been posted.

Scott

scott_mchale Tue, 03/18/2008 - 05:02

Hi Dandy

Cant see your reply, even though I received an email to advise one had been posted.

Scott

Danilo Dy Tue, 03/18/2008 - 05:13

Hi,

This means you have a free hand on the ip address range, you don't have to worry about giving the exact requirement. For example, you can give each site/department a /24 (or 255.255.255.0 network mask).

Coding example is the current International Telephone Coding Number which includes country code and area code. For example, if you use 10/8 (or 10.0.0.0/255.0.0.0).

GLASGOW: aaa

- Warehouse Staff: 0 = 10.aaa.0.0/24

- Customer Services: 1 = 10.aaa.1.0/24

- Finance: 2 = 10.aaa.2.0/24

BIRMINGHAM: bbb

- Warehouse Staff: 0 = 10.bbb.0.0/24

- Customer Services: 1 = 10.bbb.1.0/24

- Finance: 2 = 10.bbb.2.0/24

ABERDEEN: ccc/ddd

10.ccc.ddd.0/24

NEWCASTLE: eee/fff

10.eee.fff.0/24

LIVERPOOL: ggg/hhh

10.ggg.hhh.0/24

BRISTOL: jjj/kkk

10.jjj.kkk.0/24

LONDON: mmm/nnn

10.mmm.nnn.0/24

You can replace the letters with either country code or area code. If the code is higher than the valid ip address, make some adjustment. When looking at the routing table, you will be able to easily identify where the route/s came from (and where to route it).

Take note that the above is only an example. It depends if you like the idea and if you really want to follow the requirement,

Regards,

Dandy

scott_mchale Tue, 03/18/2008 - 05:25

Hi Dandy,

Thanks for your help...

To let you understand I am currently at the end of my Honours year at University, and although the above is helpful, I am afraid I am still a little confused. Is there an easier way to explain this.

Regards

Scott

Danilo Dy Tue, 03/18/2008 - 05:27

Well, you didn't mentioned this earlier. It seems that this is one of your project or something for your studies?

I guess you have to follow the requirement. Let me work on something and get back to you :)

scott_mchale Tue, 03/18/2008 - 05:38

If you have the time Dandy, I can certainly send you the document.

Scott

Danilo Dy Tue, 03/18/2008 - 05:49

Try this....

[EDIT] Glasgow Office: 10.1.0.0/22 = 10.1.0.0/24, 10.1.1.0/24, 10.1.2.0/24, and 10.1.3.0/24

- 50 Warehouse Staff (+30% = 65) = The closest subnet is 10.1.0.0/25 (maximum hosts is 126)

- 150 Customer services (+30% = 195) = The closest subnet is 10.1.1.0/24 (maximum hosts is 254)

[EDIT]- 100 Finance (+30% = 130) = The closest subnet is 10.1.2.0/24 (maximum hosts is 254)

Birmingham office: 10.2.0.0/23 = 10.2.0.0/24 and 10.2.1.0/24

- 75 Warehouse staff (+30% = 98) = The closest subnet is 10.2.0.0/25 (maximum hosts is 126)

- 100 Customer services (+30% = 130) = The closest subnet is 10.2.1.0/24 ( maximum hosts is 254)

- 75 Finance (+30% = 98) = The closest subnet is 10.2.0.128/25 (maximum hosts is 126)

Five regional sites

Aberdeen 20 staff (+30% = 26): The closest subnet is 10.3.0.0/27 (maximum hosts is 30)

Newcastle 40 staff (+30% = 52): The closest subnet is 10.3.0.128/26 (maximum hosts is 62)

Liverpool 20 staff (+30% = 26): The closest subnet is 10.3.0.32/27 (maximum hosts is 30)

Bristol 20 staff (+30% = 26): The closest subnet is 10.3.0.64/27 (maximum hosts is 30)

london 30 staff (+30% = 39): The closest subnet is 10.3.0.192/26 (maximum hosts is 62)

Other Senior NetPros may be able to advice a better combination :)

scott_mchale Tue, 03/18/2008 - 05:58

Dandy,

Thanks for your help, greatly appreciated.

Much clearer

Thanks again

Scott

scott_mchale Tue, 03/18/2008 - 06:35

Hi Dandy,

Sorry to bother you again.

Subnetting for Glasgow does not work, it works if we dont allow for 30% growth with the finance department. Or maybe I am doing something wrong. Please advise.

Glasgow Office: 10.1.0.0/23 = 10.1.0.0/24 and 10.1.1.0/24

- 50 Warehouse Staff (+30% = 65) = The closest subnet is 10.1.0.0/25 (maximum hosts is 126)

- 150 Customer services (+30% = 195) = The closest subnet is 10.1.1.0/24 (maximum hosts is 254)

- 100 Finance (+30% = 130) = The closest subnet is 10.1.0.128/25 (maximum hosts is 126)

Danilo Dy Tue, 03/18/2008 - 06:42

Yes, I noticed that, that's why I update the earlier post. Check the [EDIT] portion. Anyway, here it is

Glasgow Office: 10.1.0.0/22 = 10.1.0.0/24, 10.1.1.0/24, 10.1.2.0/24, and 10.1.3.0/24

- 50 Warehouse Staff (+30% = 65) = The closest subnet is 10.1.0.0/25 (maximum hosts is 126)

- 150 Customer services (+30% = 195) = The closest subnet is 10.1.1.0/24 (maximum hosts is 254)

- 100 Finance (+30% = 130) = The closest subnet is 10.1.2.0/24 (maximum hosts is 254)

scott_mchale Tue, 03/18/2008 - 07:49

Hi Dandy,

Everything looking good so far, just one other question.....each region also has a number (up to 5) of smaller branch sites with less than 10 staff each. So correct me if iam wrong...5 * 10= 50 for each smaller branch office....so total would be 250 * 30%...

Scott

Hi Scott

Just to add as this is for a Uni Project. The initial posting stated that the company received a range of "Class C" networks so when you are writing this up, change the first octet from "10" to any number betwen 192 and 224 as this is the range of the Class C networks. The 10.x.x.x range are (a) Class A and (b) private Class A addresses (covered by RFC 1918).

Also do not use 192.168.x.x as this is the Class C private range (covered by RFC 1918) and the initial posting stated that the range of Class C networks provided by the ISP were "Public" networks.

Best Regards,

Michael

scott_mchale Wed, 03/19/2008 - 02:17

Michael

Your time and expertise is greatly appreciated.

Many thanks

Scott

scott_mchale Wed, 03/19/2008 - 04:36

Michael,

Probably fed up with my questions, but could I ask, does this look ok!!!

Glasgow 195.168.0.0/22

Subnet Name Needed Size Allocated Size Address Mask Dec Mask Assignable Range

Customer Services 195 254 195.168.0.0 /24 255.255.255.0 195.168.0.1 - 195.168.0.254

Finance 130 254 195.168.1.0 /24 255.255.255.0 195.168.1.1 - 195.168.1.254

Warehouse 65 126 195.168.2.0 /25 255.255.255.128 195.168.2.1 - 195.168.2.126

Birmingham 195.169.0.0/23

Subnet Name Needed Size Allocated Size Address Mask Dec Mask Assignable Range

Customer Services 130 254 195.169.0.0 /24 255.255.255.0 195.169.0.1 - 195.169.0.254

Finance 98 126 195.169.1.0 /25 255.255.255.128 195.169.1.1 - 195.169.1.126

Warehouse 98 126 195.169.1.128 /25 255.255.255.128 195.169.1.129 - 195.169.1.254

Regional Sites 195.170.0.0/23

Subnet Name Needed Size Allocated Size Address Mask Dec Mask Assignable Range

Newcastle 52 62 195.170.0.0 /26 255.255.255.192 195.170.0.1 - 195.170.0.62

London 39 62 195.170.0.64 /26 255.255.255.192 195.170.0.65 - 195.170.0.126

Aberdeen 26 30 195.170.0.128 /27 255.255.255.224 195.170.0.129 - 195.170.0.158

Bristol 26 30 195.170.0.160 /27 255.255.255.224 195.170.0.161 - 195.170.0.190

Liverpool 26 30 195.170.0.192 /27 255.255.255.224 195.170.0.193 - 195.170.0.222

Branch Sites 195.171.0.0/22

Subnet Name Needed Size Allocated Size Address Mask Dec Mask Assignable Range

Small Branch_Aberdeen 65 126 195.171.0.0 /25 255.255.255.128 195.171.0.1 - 195.171.0.126

Small Branch_Bristol 65 126 195.171.0.128 /25 255.255.255.128 195.171.0.129 - 195.171.0.254

Small Branch_Liverpool 65 126 195.171.1.0 /25 255.255.255.128 195.171.1.1 - 195.171.1.126

Small Branch_London 65 126 195.171.1.128 /25 255.255.255.128 195.171.1.129 - 195.171.1.254

Small Branch_Newcastle 65 126 195.171.2.0 /25 255.255.255.128 195.171.2.1 - 195.171.2.126

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