Solved

IP addressing

Posted on 2010-09-15
8
1,087 Views
Last Modified: 2013-01-20
I have very little knowledge of IP addressing and I would appreciate some help here

I have an assigned range of 75.137.45.144/28. How many machines can I connect to it and can I make it into two equal sized subnets? How?  Is there a Math formula to figure this stuff out??
0
Comment
Question by:dawber39
  • 3
  • 2
  • 2
  • +1
8 Comments
 
LVL 35

Expert Comment

by:mccarl
ID: 33687455
You can have up to 14 devices in this range. For your info the subnet mask would be 255.255.255.240

If you want two subnets, then they could have only 6 devices each. They would have ranges of 75.137.45.144/29 and 75.137.45.152/29 and the subnet mask for these two subnets would be 255.255.255.248
0
 
LVL 69

Accepted Solution

by:
Qlemo earned 500 total points
ID: 33687474
with a /28 you have 32-28 = 4 bits = 16 addresses left for your hosts. You need to subtract two for the reserved addresses of all-zero and all-one bits, so in fact you can use 14 addresses. If you subnet that, you loose 2 addresses per subnet for the same reason. Your subnets would then be
75.137.45.144/29 with .145 - .150
75.137.45..152/29 with .153 - .158
that are 6 addresses per subnet = 12 overall.

The /28 part tells us how much bits from the left to the right are assigned to the network. Each part of the address is a single byte = 8 bit, 4 parts = 32 bits, and /28 is 32-4, which means 4 bits are left for the hosts.
We can only add bits on the highest part of the host addresses for implementing subnets, so the next bit to use for a subnet is bit 29, which has a value of 8 (2 power 3).That is why the next subnet starts at 152 (144+8).
0
 
LVL 24

Expert Comment

by:rfc1180
ID: 33687544
>I have an assigned range of 75.137.45.144/28. How many machines can I connect to it and can I make it into two equal sized subnets?

This depends on whether or not you are assigning this range to an interface; if all you are doing is defining static one to one NAT, then you can use all 16 addresses; if you are however, assigning this to a physical interface on a firewall/router, you will then need 1 IP address for the physical interface then you will have 13 usable addresses for your hosts on this LAN.

Billy
0
Microsoft Certification Exam 74-409

Veeam® is happy to provide the Microsoft community with a study guide prepared by MVP and MCT, Orin Thomas. This guide will take you through each of the exam objectives, helping you to prepare for and pass the examination.

 

Author Comment

by:dawber39
ID: 33687976
I appreciate the efforts of all of you - but Qlemo gave me a better explanation of how - thank you all
0
 

Author Closing Comment

by:dawber39
ID: 33687981
Excellent
0
 
LVL 35

Expert Comment

by:mccarl
ID: 33687997
If you "appreciate the efforts of all" you should really be sharing the points... but whatever!
0
 
LVL 24

Expert Comment

by:rfc1180
ID: 33688030
too bad you can't block authors!
0
 

Author Comment

by:dawber39
ID: 33688221
Wow - all I did was ask how - and Qlemo was quite definitive in his explanation - I am sorry if I hurt your feelings
0

Featured Post

Master Your Team's Linux and Cloud Stack

Come see why top tech companies like Mailchimp and Media Temple use Linux Academy to build their employee training programs.

Question has a verified solution.

If you are experiencing a similar issue, please ask a related question

Suggested Solutions

Network ports are the threads that hold network communication together. They are an essential part of networking that can be easily ignore or misunderstood, my goals is to show those who don't have a strong network foundation how network ports opera…
Creating an OSPF network that automatically (dynamically) reroutes network traffic over other connections to prevent network downtime.
This video shows how to use Hyena, from SystemTools Software, to bulk import 100 user accounts from an external text file. View in 1080p for best video quality.

778 members asked questions and received personalized solutions in the past 7 days.

Join the community of 500,000 technology professionals and ask your questions.

Join & Ask a Question