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Questions tagged [subnet]

Questions relating to IP subnetting, including planning, calculation and best practices.

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0answers
11 views

Find First and Last address in subnet 500 [on hold]

I need the 499th subnet first and last address Granted Block: 16.0.0.0/8
0
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1answer
34 views

IPv6 variables or other methods of shortening

From the dawn of when I heard about IPv6 many years ago, to my continued hesitance to make good use of it in today's world where it's eventually going to become necessary... my biggest issue I think ...
1
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2answers
41 views

Changing subnet mask

Currently I have a 10.10.10.0/24 network and am running out of IP Addresses. I'm not sure if I change to /22 mask, if I will still be able to communicate with some of the other facilities where we use ...
0
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0answers
12 views

How is it possible to calculate the number of subnets in a network using classful addressing? (example) [duplicate]

I'm having trouble understanding this classful subnetting concept outlined in CCENT study. https://imgur.com/a/88CbcXU I don't understand how given an IP and a mask we can work out that numerous ...
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2answers
46 views

Creating a network for three separate businesses in one building

What would be best practice in terms of creating a network to satisfy three separate businesses located in one building? The building in question has three floors, each floor has 25 workstations and ...
-1
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1answer
34 views

Find Major network vslm

Im a bit lost with this question. In order to get proceed with the vslm i need to find the Major network of this subnet 121.118.40.0 /19. For me the major network is 121.118.32.0/19, but when I run ...
1
vote
1answer
39 views

Finding the network address for given host IP?

Answer provides the procedure to find the network address when a packet with destination IP(198.51.100.223/21) is reached at a router. But a network packet has the destination IP 198.51.100.223 in ...
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0answers
27 views

ip overlapping conficting [duplicate]

123.45.0./16 i have to divide it in two rooms something like this room 1 will have 256 IP addresses and room 2 will have 512 IP addresses what i have done is this F1/0 : 123.45.0.1 255.255.255....
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0answers
19 views

What is the relationship between these numbers, how do I derive these IPs? [duplicate]

How do I derive the following IPs / what is the relationship between them? I'm 99% sure I can understand the answer if someone just throws the right keyword at me. I haven't done networking in a while ...
-1
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0answers
15 views

how would i calculate subnets [duplicate]

Design a network environment which has been allocated 123.45.0.0/16 address space the two room names are room_1 and room_2 each room has two subnets staff subnet and user subnet Divide the ...
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votes
1answer
20 views

Why CIDR block is assigned to subnet? [duplicate]

If VPC is assigned CIDR block 172.31.0.0/16, then I can create sub-nets within VPC, following this procedure: 172 . 31 . 0 . 0 255 . ...
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0answers
29 views

Unifi port forwarding as firewall rule

I got an USG and i am using it as an PPPoE router. Port forwarding is working. But it is not working to set a "limited IP". It is very important that just one IP can access the server from the ...
3
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3answers
120 views

What is the actual purpose for having a 1:1 ratio between VLANs and subnets?

I understand the technical difference between a subnet and a VLAN. After looking through questions related to this topic, including: VRFs, VLANs and subnets: difference VLANS vs. subnets for network ...
3
votes
3answers
473 views

A VLAN maps several subnet

I've read the post Multiple Subnets in a VLAN and am wondering about the possible conflicts when using several subnets in a VLAN. The recommended design is of course put a IP subnet in a VLAN. If I ...
0
votes
2answers
22 views

Sonicwall DHCP Reserved IPs Broken After Expanding Subnet

I've just expanded our subnet at work from /24 to /22 now that we've started running out of IPs. For ease of transition, I left all statically-assigned IPs at their original addresses and moved the ...
0
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1answer
80 views

IP Addressing-Why All zero(0) and all one(1) in subnet id bits are reserved?

I'm studying about class less inter domain routing. I've come to know that all zeros(0) in host id bits refers to subnet address and all ones(1) in host id bits refers to broad cast address. So, ...
1
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2answers
30 views

How can subnets not fulfil symmetric property?

While studying Internet Protocol, I came upon the following example of two devices: Device A: IP address: 10.1.1.1 Subnet mask: 255.255.255.0 and Device B: IP address 10.1.1.200 Subnet mask 255....
1
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1answer
31 views

IP Routing question

We are in the process of replacing our firewall and are keeping the VPN client traffic on the older device. The public IP range is being split between the two devices from our border router. All the ...
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0answers
9 views

Linux: How to talk to two VLANs that have the same addressing? [duplicate]

I need to read PLCs from two vendors. These vendors used the same adressing for their PLCs (192.168.1.x), and the IP addresses collide (both PLCs are 192.168.1.2). The two networks are basic (no VLAN)....
7
votes
1answer
231 views

Is the first address of the subnet a valid configurable address in case of IPv4 and IPv6 point to point networks?

Am I correct, that first address of the subnet is a valid addresses to configure in hosts/routers in case of IPv4 and IPv6 point to point networks? For example, in case of 192.0.2.0/31 one of the ...
0
votes
1answer
38 views

What happen if broadcast is made to first and last address of other network?

Broadcast to network id What happens if you broadcast to the first IP of another network ? broadcast to broadcast id of another network What happens if you broadcast to the last IP of another ...
1
vote
1answer
28 views

I am trying to set up aDHCP server in a VLAN for practical of networking with Linux

I am a Linux user requesting advice about setting up a DHCP with a VLAN based on offices on one floor for the practical purpose. Is this good enough for implementing a VLAN structure with a DHCP ...
3
votes
1answer
59 views

Can't ping the management IP of Switch

My topology is: I am logged in to R1. I can ping 10.0.0.2 on R2 and 198.51.100.1 on R2, but can't ping the management IP of sw3 (198.51.100.2). What am I doing wrong? R1#sh ip arp Protocol Address ...
5
votes
2answers
186 views

Carrying remote VLAN via 2 routers to the local gateway

I have a serverA (192.168.15.1) from site A and VLAN is 15, however the VLAN 15 gateway is set at site B (192.168.15.254). There are two ISP routers as a metro role to connect each other by subnet ...
2
votes
1answer
44 views

My OSPF Multi Area Topology is not reliable

I made an ospf multi area topology, but it's inconsistent. At times, host from the A area could ping to hosts in other areas however, sometimes otherwise (failed to arrive). Whenever I tried to do a ...
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votes
1answer
64 views

Dividing IPv4 Network into 7 Subnets? [duplicate]

I've been trying to figure out how to divide a network IPv4 IP Address into 7 subnets, where each subnet requires a different number of hosts. For example I have the question: "You are an intern at ...
3
votes
1answer
221 views

How to connect 192.168.1.x network to 192.168.100.x gateway?

Hello fellow networkers. I am very new to this world and don't know a great deal about IP addresses and subnetting. I however stumbled upon quite a big problem (for me at least - haha) My entire ...
0
votes
1answer
83 views

(CISCO Packet Tracer) Overlap Error

I am trying to set up a network of for different organisational departments based on a given typology: Using Cisco 2911 routers & 2960-24TT Switches. With given addressing of: 'EIGRP 101' 172....
2
votes
1answer
51 views

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 ...
2
votes
2answers
272 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 ...
4
votes
2answers
65 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 ...
2
votes
1answer
50 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 ...
1
vote
3answers
64 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 ...
1
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0answers
49 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. ...
1
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2answers
57 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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1answer
44 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 ...
1
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1answer
71 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
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6answers
614 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
votes
1answer
227 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 ...
0
votes
1answer
44 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 ...
1
vote
2answers
43 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
votes
2answers
141 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
votes
1answer
76 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
vote
1answer
824 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.
1
vote
3answers
192 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 ...
0
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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
votes
1answer
434 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 ...
2
votes
3answers
797 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 ...
1
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1answer
130 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 ...