Questions relating to IP subnetting, including planning, calculation and best practices.
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Subnetting Access Problem
I am learning subnetting, and I am using Packet Tracer to design a network for a building with five storeys. I have used subnetting, with each floor having its own subnet. As a result, it is not ...
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0answers
11 views
Communication across subnets [on hold]
Ok, So first things first: I know what a subnetmask is, and what it is used for. But I have no idea how to properly set it
Above is my home network, I have my dhcp server set to the router (192.168.0....
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0answers
9 views
Can we use directed broadcast as limited broadcast? See scenario below [on hold]
I am learning Computer Networks and was reading about limited and directed broadcast.
So, can we use option C to do the task required as the directed broadcast(destination) is aiming at its own ...
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2answers
249 views
Is Subnetting the Way to Configure this Network?
I have roughly 20 devices connected to a switch and want to divide them up by their different functions. Some devices are sensors, some are motor controllers, there's a data-logger, and a PC to ...
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10 views
Determine IP Pool or subnet IP [on hold]
OS - Ubuntu 16.04
I was taught in class to do this :
host google.com
copy the output IP then
whois <copiedIP> | grep CIDR
this gave the network ID with the subnet mask and hence gave the IP ...
3
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2answers
56 views
Whether we usual use dot-decimal notation to represent network or IP by opposite mask?
Whether we usual use dot-decimal notation to represent network or IP by opposite mask?
10.10.10.0 0.0.0.255 # a network
10.10.10.0 255.255.255.0 # a IP
Update
if we represent a network, we can use ...
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0answers
10 views
Calculate supernet of host and host number based on IP and mask? [duplicate]
So I got the following IP: 192.15.205.7 and the following mask: 255.255.252.0.
Now I know that in order to get the supernet of the host I have to use the AND operator between the IP and the mask.
In ...
1
vote
1answer
46 views
Network discovery and establishing connections within Eduroam, a network split in subnets
For our current project we are supposed to create a peer2peer (no server) game application which is played by a teacher and his students on the Eduroam network. The concerns of the stakeholder ...
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21 views
Doubt on subnetting [duplicate]
I am learning basics of networks and I have the following doubts:
Is the following statement true?
Subnet mask of a network = Subnet mask of all hosts in the network.
My instructor gave an example ...
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3answers
35 views
Two ports both in VLAN 1 on two separate switches down/down
For someone who recently got their CCENT, I feel kind of stumped.
I have two switches, both are Cisco 3550s. I am using VLAN 1 as a management vlan and on S1, I assigned IP address 10.24.0.11/24 to ...
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0answers
24 views
Network segmentation with VLAN and MAC auth: thoughts about implementation
Currently we have a medium-sized, flat network with some DHCP pools. This configuration isn't satisfying us anymore, as everyone can see everything on the network and it may leads to security issues. ...
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2answers
40 views
Why Do we consider the serial connection between routers a subnet?
The image attached was included in a question where I was required to design the network f0r the classful network address 172.16.0.0, and it says that each circle represents a subnetwork. My question ...
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22 views
Configuring Sonicwall using Multiple WAN IPs and multiple LANs
so I am attempting to configure a Sonicwall NSA 3600 in a fairly complex setup... I know this is long, I wanted to explain my full setup and goal. YOU CAN SKIP TO THE END FOR SOME GENERAL QUESTIONS. ...
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0answers
30 views
Can you explain this IP address/subnet question? [duplicate]
If I have an IP address and subnet mask combination of 192.168.204.255/24, and my default gateway for a network is 192.168.204.254. How can I make so that I can connect to the network?
I'm failing to ...
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0answers
16 views
Find subnet's address from subnet's mask? [duplicate]
Can someone find subnet's address that a node belongs from the subnet's mask?
For example this subnet's mask: 255.255.248.0
IP: 8.20.15.130
248 is subnet's address right? If yes the way to find it ...
0
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1answer
35 views
How to differentiate between classful network and subnet (beginner)? [duplicate]
I have just started learning from the ICDN1 official Cert book.
I've just covered the concept of Classful Networks.
However when introducing Subnetting, the example has me confused.
It examples an ...
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0answers
19 views
Why do some subnets have the same broadcast address? [duplicate]
If I have a B Classful address, 172.20.0.0, and I need 50 hosts, I pick, 255.255.252.0 for the subnet mask after borrowing the bits and so on, 127.20.0.0/22.
But what I don't understand is why when I ...
0
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1answer
33 views
How can I create a static route between subnets on sonicwall
I have a SonicWall and two Wifi Access Points (APs) connected to it.
The secured WLAN AP is connected to port X0 with subnet 192.168.22.x and has our "Secure" clients, as well as a printer.
The guest ...
4
votes
6answers
483 views
Why is classful addressing considered waste?
I am trying to understand the addressing strategies. But there is something which I can't grasp. Maybe I am missing a very basic point, if so, I am sorry beforehand.
From my researches, let's say, if ...
0
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0answers
3 views
Is it commonplace / accepted to change an existing CIDR prefix to meet certain network requirements? [duplicate]
Say for example, you have an IP address with a CIDR prefix of /27 (mask of 255.255.255.224) and are required to create 4 subnets each with an equal amount of usable host addresses, would it be ...
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0answers
6 views
how to find the answer and what the answer is to each one of these questions borroed bits bits remaining subnet mask number of hosts per subnet etc [duplicate]
Answer following questions about the 192.168.70.0/26 address.
What is the subnet mask?
What is the number of bits borrowed?
What is the number of bits remaining in the host part?
What is the ...
0
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1answer
78 views
How to assign 2000 addresses starting from 198.16.16.0? [duplicate]
This problem comes from Tannanebaum's CN book and the full description of it is as follows:
A large number of consecutive IP addresses are available starting at 198.16.0.0. Suppose that four ...
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1answer
43 views
Why is devices on Subnet 2 (Router 2) can access devices on Subnet 1 (router 1) but not vice versa? [closed]
I am new to the world of network so please bear with me. I have chained two routers to create two subnet at my home. I have two routers and second router is connected to my ISP ADSL modem router by ...
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2answers
36 views
Advice on potentially needed subnet expansions
I work for a non-profit with some slightly more antiquated hardware. We have 3 locations, about 700 devices across them. Right now our locations are set up as:
Location 1 (Main) - /23 with a DHCP ...
3
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2answers
84 views
How does the ARP table work in case of the Gateway Router?
Suppose I am a host, I understand how ARP works in case I address an IP within my subnet. For each IP address there is a corresponding MAC address, and the owner responds to my broadcast ARP query. ...
0
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1answer
42 views
Are there any constraints to Subnetworks? [duplicate]
Using this network mask 255.255.255.0, I can steal 2 bits from the host bits to make 4 subnets.
Now I've never seen it but is it also possible to use the NWMask 255.255.0.0 and also create 4 ...
1
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1answer
445 views
Find subnet prefix/CIDR from IP address and required No of hosts [duplicate]
I want to know that how can we calculate the Subnet prefix and CIDR, when the given information is only IP address and required No of hosts. For example: Suppose we have:
IP Address= 198.1.1.0 and ...
17
votes
1answer
3k views
What is the practical use of a /31 CIDR or 255.255.255.254?
With a /31 subnet, we are left with zero usable hosts. The /31 subnet only has two hosts - one for network and another for broadcast.
I am wondering why would someone ever use this subnet.
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3answers
133 views
how to do inter vlan for same subnet
I configure two same subnet network(ip:192.168.0.2 & ip:192.168.0.3) into VLAN...so they wont communicating with each other...but now i want them to communicate with each other...
For that i ...
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0answers
7 views
How to find subnet mask using First and last usable IP address [duplicate]
The first and the last IP addresses of a subnet are 192.192.8.0 and 192.192.63.255 respectively. how to find the subnet mask?
2
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1answer
363 views
Can a 172.168.10.0/28 be a class B Subnet
I am starting my studies in networking and starting off with the basics of IP addressing and Subnetting with CIDR values.
My Question here is 1st how can you tell the subnet class of an IP address ...
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3answers
320 views
If there's no response to the ARP request, will the host send to its default gateway?
Host A and B are on the same subnet. A sends ARP request(s) asking for B's MAC. For whatever reason, B doesn't respond. Will A either:
Give up -- it can't reach B
Send the packet to the default ...
0
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1answer
86 views
What are the component names of CIDR Prefix Notation?
What are the components of the IETF's CIDR Prefix Notation called?
172.16.0.0/16 contains two parts:
172.16.0.0
/16
In the RFC the entire term 172.16.0.0/16 is defined as the "Prefix Notation" for ...
2
votes
2answers
82 views
Bad mask for Cisco simulator GNS3
I am using the GNS3 simulator, and I need to connect two Cisco C7200 routers.
When I enter the ip address 126.0.0.4 255.255.255.252 command, I get Bad mask /30 for address 126.0.0.4.
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2answers
55 views
please explain to me [closed]
so at our company we use a program for people to track vehicles but you see the only way the people can get access to this program if the subnet mask is 255.255.254.0. and when i put the ip on dhcp it ...
0
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1answer
192 views
Can a VLAN have hosts with IP addresses outside it Subnet IP range scope?
I have 3 entities in my network.
A server,switch and an appliance which acts as a DHCP/PXE server.
When the server starts up, the DHCP server has to PXE boot the server. A seperate VLAN(1234) is ...
1
vote
1answer
76 views
What format is "1.34.128.0/113'?
I know of two format that use similar notation, Classless Inter Domain Routing (CIDR) and Variable Length Subnet Mask (VLSM). However the numbers after the / is usually less than 32. However in this ...
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vote
1answer
179 views
Same subnet on two firewalls
I came across a network setup in this way:
Cisco device provided by the ISP serving as a bridge between the fibre line and the LAN.
Cable coming out from port eth0 of the Cisco above going to a ...
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0answers
4 views
Attempting to understand how to reason through number of available subnets [duplicate]
Hopefully this question isn't too trivial. I'm studying for my network+ and I got thrown for a loop on a practice question. I can do the "mechanical" work but I would really like to understand why ...
6
votes
1answer
298 views
Why is an IPv6 Link-Local Address a /10?
I'm currently studying for my CompTIA Network+ Exam and am a bit confused as to why the IPv6 link-local address is a /10 and not a /12 or /16. Since each character in an IPv6 address is 4-bits and ...
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0answers
13 views
Which of the following is the minimum subnet mask to allow 172.16.1.5 and 172.16.4.3 to be on the same subnet [duplicate]
Can someone please help in explaining the answer to this question
Which of the following is the minimum subnet mask to allow 172.16.1.5 and 172.16.4.3 to be on the same subnet?
A. /19
B. /21
C. /22
...
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0answers
14 views
Subnetting Questions [duplicate]
I have some questions about subnetting that I can't figure out myself. I am studying fora test just don't understand what to do with subnets. I have an IP address, 128.232.242.0/25 and I need to crate ...
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2answers
58 views
Before the invention of Classless Inter-Domain Routing (CIDR) did hosts have subnet masks assigned?
Before the invention of CIDR, did hosts also have a subnet mask assigned or only have an IP address and the network was determined by the class of the IP address?
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1answer
48 views
Router IP between networks of different classes
I have 2 networks that I want to ping each other, one of the networks uses class B 172.16.16.0/19 and the other network is class C 192.168.0.0/26. Both networks have their own subnets and vlans, and ...
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2answers
146 views
Access a subnet through another network
We have some devices connected together through a switch. We need to access them through another network, but because of IP counts limitation we cant get IP from that network.
Q: How to access my ...
6
votes
3answers
772 views
Why couldn't a nework address be used as as broadcast address as well?
I am taking a refresher on Networking and I found out that:
Network address is an IP address with all 0s after the subnet mask
Broadcast address is an IP address with all 1s after the subnet mask
...
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0answers
12 views
Subnetting to Specific Requirements [duplicate]
I have an assignment with a couple of questions I'm trying to get my head around. I wont go into specifics, but basically.
I have been given one address, lets make it 150.110.0.0/16.
It asks to ...
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1answer
28 views
VLSM Network Devices
hi guys, so when my lecturer was explaining the process to do vlsm, they mentioned that for every cable linking to a device, you are suppose to add 2. eg(200,100,50,2*number of cable). but from what i ...
3
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1answer
72 views
VLSM Determining Switch IP
i was given a network 130.4.0.0/16 that i needed to use vlsm on. which i did and got these vaules:
Address | Mask| Assignable Range | Broadcast
130.4.0.0 | /22 | 130.4.0.1 - 130.4.3.254 | ...
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2answers
132 views
How to avoid a routing loop in a 'subnet of a subnet'?
This question is motivated by the example given near the end of Cisco's article on Subnet Zero and the All-Ones Subnet (from the subsection titled The All-Ones Subnet), but I include all necessary ...
