Networking question on determining the IP

  • Thread starter Thread starter Darkstar3000
  • Start date Start date
  • Tags Tags
    Networking
Click For Summary

Discussion Overview

The discussion revolves around assigning IP addresses to devices in a given network diagram, focusing on the identification of network and host parts of IP addresses. Participants explore the classification of IP addresses (Class A, B, C) and the implications for address assignment.

Discussion Character

  • Homework-related, Technical explanation, Conceptual clarification

Main Points Raised

  • Some participants express confusion about how to assign IP addresses based on the network diagram provided.
  • One participant references the definition of an IP address, noting the distinction between network identification and host identification.
  • There is a discussion about the classification of IP addresses, with some participants identifying their addresses as Class A and Class C.
  • Participants discuss the arbitrary nature of the host identification portion of the IP address, with examples given for potential addresses.
  • Clarifications are made regarding the structure of IP addresses, emphasizing that they must consist of exactly four octets.
  • One participant questions whether they can use different numbers for the host identification while maintaining the network identifier.
  • There is a mention of a reputation system on the forum, with participants discussing the lack of a "like" or "thanks" button.

Areas of Agreement / Disagreement

Participants generally agree on the structure of IP addresses and the classification into classes, but there is some uncertainty regarding specific assignments and the implications of those classifications. The discussion remains unresolved on some points, particularly regarding the assignment of arbitrary values within the constraints of network identification.

Contextual Notes

Participants express confusion about the assignment process, indicating a need for further clarification on the rules governing IP address structure and classification.

Darkstar3000
Messages
28
Reaction score
0
Consider the simple network shown below:

http://img856.imageshack.us/img856/8966/wrwrwr.png

Write down an IP address for all interfaces at all hosts and routers in the network. The IP addresses for A and E are as given. You should assign IP addresses so that interfaces on the same network have the same network-part of their IP address. Indicate the number of bits in the network-part of this address.

///////////////////////////////////////

This question is in one of my assignments and I have no idea on how to do it, I've tried looking up any relevant information but found nothing. How would I go about calculating the IP address of all the devices ?
 
Last edited by a moderator:
Physics news on Phys.org
Darkstar3000 said:
Consider the simple network shown below:

http://img856.imageshack.us/img856/8966/wrwrwr.png

Write down an IP address for all interfaces at all hosts and routers in the network. The IP addresses for A and E are as given. You should assign IP addresses so that interfaces on the same network have the same network-part of their IP address. Indicate the number of bits in the network-part of this address.

///////////////////////////////////////

This question is in one of my assignments and I have no idea on how to do it, I've tried looking up any relevant information but found nothing. How would I go about calculating the IP address of all the devices ?

Hi Darkstar! :smile:

Let's start with the wikipedia definition of an IP address:
http://en.wikipedia.org/wiki/IP_address

The first part of an IP address is the network identification.
The second part is the host identification.
It depends on the type op IP address where the separation between the two is.
That is, whether it is a class A, class B, or class C network address.

Can you tell which classes your given IP addresses are?
 
Last edited by a moderator:
I like Serena said:
Hi Darkstar! :smile:

Let's start with the wikipedia definition of an IP address:
http://en.wikipedia.org/wiki/IP_address

The first part of an IP address is the network identification.
The second part is the host identification.
It depends on the type op IP address where the separation between the two is.
That is, whether it is a class A, class B, or class C network address.

Can you tell which classes your given IP addresses are?
I'm guessing that mine is a class A since "Range of first octet (decimal) for class A is 0 - 127"

and based on the information you've provided the 2 computers on the left will have "111.111." as the beginning of their ip addresses
 
Close.
On the left you have indeed class A addresses.
The netwerk identification is the first octet (the second is not part of it).
So the 2 computers on the left start with "111.".
The second part is an arbitrary choice, although 0.0.0 (any-mask) and 255.255.255 (broadcast) have special meanings, so you shouldn't use those.
Any other choice is fine, just pick one (or rather two ;).

What about the IP addresses on the right?
 
I like Serena said:
Close.
On the left you have indeed class A addresses.
The netwerk identification is the first octet (the second is not part of it).
So the 2 computers on the left start with "111.".
The second part is an arbitrary choice, although 0.0.0 (any-mask) and 255.255.255 (broadcast) have special meanings, so you shouldn't use those.
Any other choice is fine, just pick one (or rather two ;).

What about the IP addresses on the right?

I like Serena said:
Close.
On the left you have indeed class A addresses.
The netwerk identification is the first octet (the second is not part of it).
So the 2 computers on the left start with "111.".
The second part is an arbitrary choice, although 0.0.0 (any-mask) and 255.255.255 (broadcast) have special meanings, so you shouldn't use those.
Any other choice is fine, just pick one (or rather two ;).

What about the IP addresses on the right?

So it I can assign computer B to have it's address as 111.2.111 or does the last part change to 112 ? or does the middle part need to be 3 digits as well

and on the right we have class C and the computer would have the address 222.3.222 or something similar ?

I'm sorry if my questions sounds stupid, I'm just really confused
 
B can have any host identification of 3 octets, for instance 111.2.111 or 0.0.2.
You still have to prefix it with the network identification, which is 111.
So B could be for instance 111.111.2.111 or 111.0.0.2.
An IP address always consists of 4 octets (each octet is in the range 0-255).

On the right we have indeed a class C network, meaning the first 3 octets (24 bits) identify the network, which is 222.222.222 (but not 222.2.222, where did you get that?).
 
I like Serena said:
B can have any host identification of 3 octets, for instance 111.2.111 or 0.0.2.
You still have to prefix it with the network identification, which is 111.
So B could be for instance 111.111.2.111 or 111.0.0.2.
An IP address always consists of 4 octets (each octet is in the range 0-255).

On the right we have indeed a class C network, meaning the first 3 octets (24 bits) identify the network, which is 222.222.222 (but not 222.2.222, where did you get that?).

Since the second part is arbitrary, does that mean that my address for computer B can also be 111.111.7.111 ?


I was using 222.2.222 as an example answer for computer D (on the right).
 
Darkstar3000 said:
Since the second part is arbitrary, does that mean that my address for computer B can also be 111.111.7.111 ?

Yep!


I was using 222.2.222 as an example answer for computer D (on the right).

Not an option.
The first 3 octets must be 222.222.222 since that identifies the network.
You can only choose the last octet.
 
I like Serena said:
Yep!




Not an option.
The first 3 octets must be 222.222.222 since that identifies the network.
You can only choose the last octet.


Alright, got that part. Thank you


So computer D is going to have to be 222.222.222.222.6 (6 being arbitrary as well ?) ?
 
  • #10
Nope. Sorry. An IP address has to consist of exactly 4 octets (not 5).
 
  • #11
I like Serena said:
Nope. Sorry. An IP address has to consist of exactly 4 octets (not 5).


So 222.222.222.6 ?

In the previous post I put an extra octet because I thought I needed to use the network identifier as the prefix
 
  • #12
Yes. The network identifier has to be there as a prefix.
That leaves only 1 octet for the host identifier.
So 222.222.222.6 is indeed a proper IP address for computer D.
 
  • #13
Thank you very much.So basically all I have to do is remember the class and assigning addresses would be this simple ?

Is there a reputation system on this website ?
 
  • #14
The "network" identifier is "222.222.222".
The host identifier in this case would be "6",
 
  • #15
I like Serena said:
The "network" identifier is "222.222.222".
The host identifier in this case would be "6",

I managed to figure that out from your previous post. once again, Thank you
 
  • #16
You're welcome. :)

Darkstar3000 said:
Is there a reputation system on this website ?

Reputation system? :confused:
 
  • #17
I like Serena said:
You're welcome. :)
Reputation system? :confused:

You know, like thanking someone in a thread for helping them
 
  • #18
Ah, okay.

I'm afraid we do not have "like" or "thanks" buttons on PF.
We have medals that are assigned by staff.
And we have awards that result from elections (only in december).

Until the next december the only thing a member can do is write thanks in regular posts.
 
  • #19
I like Serena said:
Ah, okay.

I'm afraid we do not have "like" or "thanks" buttons on PF.
We have medals that are assigned by staff.
And we have awards that result from elections (only in december).

Until the next december the only thing a member can do is write thanks in regular posts.

Oh I see. Well I guess I've thanked you enough, I'll get on with the rest of my assignment :P
 

Similar threads

Comp Sci Current broadcast address+1 for next subnet network address?
  • · Replies 3 ·
Replies
3
Views
4K
What can be the answer for this question -- Datapath through 3 routers
  • · Replies 3 ·
Replies
3
Views
2K
Networking, subnetting and router IP
  • · Replies 20 ·
Replies
20
Views
4K
IP Router & IP Forwarding Table
  • · Replies 1 ·
Replies
1
Views
3K
Connecting extra IPs on a server
  • · Replies 4 ·
Replies
4
Views
2K
Comp Sci How Comprehensive Should an Undergraduate Explanation of MPLS Be?
  • · Replies 1 ·
Replies
1
Views
1K
Set subnet mask to allow connections to two different class c networks
  • · Replies 13 ·
Replies
13
Views
2K
Understanding Subnet Masks and IP Addresses in Computer Networking
  • · Replies 16 ·
Replies
16
Views
5K
Using a modem in a LAN to access the Internet
  • · Replies 27 ·
Replies
27
Views
4K
IP Address Assignment: How are IP Addresses Assigned?
  • · Replies 10 ·
Replies
10
Views
3K