07-24-2012 07:37 PM - edited 03-07-2019 07:57 AM
On this problem I have subnet the given ip, connect router 1 and 2 but 2 and 3 seems to be difficult to be connect because I get confused on the subneting. I have 60 percent of this problem but I won't pass that percent. I am stuck anybody can give me a hand.
THE PROBLEM...
Device | Interface | IP Address | Subnet Mask | Default Gateway |
R1 | Fa0/0 | N/A | ||
S0/0/0 | ||||
S0/0/1 | ||||
R2 | Fa0/0 | N/A | ||
Fa0/1 | ||||
S0/0/0 | ||||
S0/0/1 | ||||
R3 | Fa0/0 | N/A | ||
S0/0/0 | ||||
S0/0/1 | ||||
PC-1A | NIC | |||
PC-1B | NIC | |||
PC-1C | NIC | |||
Eagle_Server | NIC |
Practice your network building, planning, and configuration skills. Device names and routing have already been configured.
Use the following chart, and the devices in the Device Pool, to create the topology.Routers:
Hostname | Interface | Connects To | Interface |
R1 | Fa0/0 | SW-1 | Fa0/1 |
R1 | S0/0/0 (DCE) | R2 | S0/0/0 |
R1 | S0/0/1 (DCE) | R3 | S0/0/1 |
R2 | Fa0/0 | SW-2A | Fa0/1 |
R2 | S0/0/1 (DCE) | R3 | S0/0/0 |
R2 | Fa0/1 | SW-2B | Fa0/1 |
R3 | Fa0/0 | SW-3 | Fa0/1 |
Switches:
Hostname | Interface | Connects To | Interface |
SW-1 | Fa0/2 | PC-1A | FastEthernet |
SW-2A | Fa0/2 | PC-1B | FastEthernet |
SW-2B | Fa0/2 | Eagle_Server | FastEthernet |
SW-3 | Fa0/2 | PC-1C | FastEthernet |
You are asked to use the 192.168.1.0 /24 address space. Seven total networks are required; assign the networks in decreasing order of number of hosts required for efficient use of address space. Use the following charts to create an effective addressing scheme:LAN:
Hostname | Interface | Number of Hosts |
R1 | Fa0/0 | 60 |
R2 | Fa0/0 | 10 |
Fa0/1 | 25 | |
R3 | Fa0/0 | 7 |
WAN:
WAN Links | Address to be Assigned | Number of Hosts |
R1-R2 | R1-First host address | 2 |
R1-R3 | R1-First host address | 2 |
R2-R3 | R2-First host address | 2 |
Use the following rules to assign the IP addresses.
Perform interface configuration of the R1, R2, and R3 routers, the PCs, and the server according to the addressing scheme above.
Make sure all PCs can ping their gateways, other PCs, and the server.
All contents are Copyright © 2007–2009 Cisco Systems, Inc. All rights reserved. This document is Cisco Public Information.
07-24-2012 09:24 PM
I would recommend Cisco Learning Network for this type of question.....its more of student forum. But since your here!,
what part are you getting stuck with? Just th concept in general?
To get subnetting you really have to do question after question after example after example after question after example after question after question after example after example after question after example...you get the point.
Here is a site I used alot:
http://www.subnettingquestions.com/
It sounds to me as if you might be confused with the concept of subnetting in general....does the concept confuse you or the math?
07-26-2012 07:09 AM
What confused me was the math, the sequence of events. I tend to confuse the assigning the first usable host, with the network part and the broadcast address.. therefore the math tend to get confuse in between subnets.
07-24-2012 11:23 PM
Hi,
192.168.1.0/24
1st subnet: 60 hosts
==>6 host bits ==> 32-6=26 ==> /26 ==> 255.255.255.192
so the available subnets are:
192.168.1.0/26
192.168.1.64/26
192.168.1.128/26
192.168.1.192/26
we take the first one for R1 f0/0: 192.168.1.0/26
All FastEthernet ports on a router will use the last host address of the assigned subnet.
==>the available adresses are 192.168.1.1- 192.168.1.62 ==> f0/0 R1 is 192.168.1.62/26
2nd subnet: 25 hosts
==> 5 host bits ==> 32-5=27 ==> /27 ==> 255.255.255.224
so the available subnets are:
192.168.1.64/27
192.168.1.96/27
192.168.1.128/27 and so on
==> we take the first one:192.168.1.64/27 : 192.168.1.65-192.168.1.94
==> R2 f0/1 is 192.168.1.94/27
3rd subnet: 10 hosts
==> 4 host bits ==> 32-4=28 ==> /28 ==> 255.255.255.240
so the available subnets are:
192.168.1.96/28
192.168.1.112/28
192.168.1.128/28
192.168.1.144/28
and so on
==> R2 f0/0 is 192.168.1.110/28
4th subnet: 7 hosts
==> 4 host bits => /28 ==>255.255.255.240
available subnet is 192.168.1.112/28 ==> R3 f0/0 is 192.168.1.126/28
Now for the serial links we need /30 subnets
for that we subnet 192.168.1.128/28 which gives us:
192.168.1.128/30: 192.168.1.129-192.168.1.130
192.168.1.132/30: 192.168.1.133-192.168.1.134
192.168.1.136/30: 192.168.1.137-192.168.1.138
==>R1-R2 R1 is 192.168.1.129/30 and R2 is 192.168.1.130/30
R1-R3: R1 is 192.168.1.133/30 and R3 is 192.168.1.134/30
R2-R3: R2 is 192.168.1.137/30 and R3 is 192.168.1.138/30
Regards.
Alain
Don't forget to rate helpful posts.
07-26-2012 07:11 AM
Thank you for your great explanantion though I didn't understand this
2nd subnet: 25 hosts
==> 5 host bits ==> 32-5=27 ==> /27 ==> 255.255.255.224
Why you substract -5 from 32?
07-26-2012 07:41 AM
Hi,
because an IPv4 address is 32 bits long and I need to leave 5 bits for the hosts to have enough usable addresses
and so the rest are network + subnetwork bits which gives me the prefix-length that I can then equate to subnet mask.
Regards.
Alain.
Don't forget to rate helpful posts.
07-26-2012 07:32 PM
Are the links connected through the S/0/0?
07-26-2012 10:50 PM
which links are you talking about ?
Regards.
Alain
Don't forget to rate helpful posts.
07-27-2012 05:43 AM
i am talking about the serials links i don't understand why the program tracer is saying that the ip are overlapping, specially the links ones after the sunbnet .129
07-27-2012 06:24 AM
Hope this clears it up....I will leave the rest to you.
Mike
Requirements in Decending order | Subnet with a mask of | Network Address (Not a usable IP Address) | Broadcast Address (Not a usable IP Address) | Total number of IP addresses | Usable IP addresses | |
60 host subnet | 192.168.1.0 | 255.255.255.192 | 192.168.1.0 | 192.168.1.63 | 64 | 62 |
25 host subnet | 192.168.1.64 | 255.255.255.224 | 192.168.1.64 | 192.168.1.95 | 32 | 30 |
10 host subnet | 192.168.1.96 | 255.255.255.240 | 192.168.1.96 | 192.168.1.111 | 16 | 14 |
7 host subnet | 192.168.1.112 | 255.255.255.240 | 192.168.1.112 | 192.168.1.127 | 16 | 14 |
2 host network Serial connection from R1 to R2 | 192.168.1.128 | 255.255.255.252 | 192.168.1.128 | 192.168.1.131 | 4 | 2 |
2 host network Serial connection from R1 to R3 | 192.168.1.132 | 255.255.255.252 | 192.168.1.132 | 192.168.1.135 | 4 | 2 |
2 host network Serial connection from R2 to R3 | 192.168.1.136 | 255.255.255.252 | 192.168.1.136 | 192.168.1.139 | 4 | 2 |
07-27-2012 06:35 AM
i will get on it right now thanks for the push and homework left.
07-27-2012 06:39 AM
Just make sure you understand what I did for future.
Remember to rate helpful posts...
Mike
07-27-2012 07:55 AM
i am 97% percent now. i did understood the sequence of event which is in
LAN:
Hostname | Interface | Number of Hosts |
R1 | Fa0/0 | 60 |
R2 | Fa0/0 | 10 |
Fa0/1 | 25 | |
R3 | Fa0/0 | 7 |
WAN:
WAN Links | Address to be Assigned | Number of Hosts |
R1-R2 | R1-First host address | 2 |
R1-R3 | R1-First host address | 2 |
R2-R3 | R2-First host address | 2 |
i was getting the subnetting all mixed up and didn't know which one to subenet first. your and cadet where extremenly helpful and now i know that for the future i will have to follow that sequence.
The only thing that appear to be missing is the type for the switches
When i click on check results there is a tab called type which has an red X indicating that i have to configure that part i don't know what to put. i don;t know if they mean DNS and Http server settings.
Never mind.........
the type refered to the cable. i was connecting the switch with the server with a cross over cable and it needed a straight through cable...
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