Questions relating to IP subnetting, including planning, calculation and best practices.
0
votes
1answer
10 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
367 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
0answers
12 views
How to route all the traffic from wlan0 to eth0 and making ip given to wlan0 act as a gateway? [closed]
I have 2 laptops both connected on the same LAN using wifi. In One laptop I have a working internet connection which I shared to laptop 2 using Ethernet, as I wanted to create a new gateway on the ...
0
votes
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 ...
0
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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
votes
1answer
45 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 ...
-1
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0answers
22 views
What is the network address of this subnet? [duplicate]
I need help solving this question as i am not very good in networking lingo.
Insert the Layer 2 and Layer 3 addresses used the following transfer from computer A to computer B. How many IP Addresses ...
0
votes
1answer
42 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 ...
0
votes
2answers
35 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
67 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
28 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
114 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
79 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
votes
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
321 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 ...
1
vote
3answers
88 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
votes
1answer
53 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
57 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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votes
2answers
52 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
votes
1answer
80 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
74 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 ...
1
vote
1answer
95 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 ...
0
votes
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
104 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 ...
0
votes
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
...
0
votes
0answers
13 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 ...
2
votes
2answers
51 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?
-1
votes
1answer
42 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 ...
0
votes
2answers
117 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
766 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
...
0
votes
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 ...
0
votes
1answer
26 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
votes
1answer
57 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 | ...
0
votes
2answers
104 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 ...
4
votes
3answers
902 views
How will be the ARP Request (Unicast/Broadcast) if Subnet Mask is Unknown
Please help me with one doubt regarding ARP requests. Based on my understanding the subnet of an IP is identified by it's Subnet Mask so consider this scenario:-
Suppose Device1 with IP- 30.129.33....
0
votes
1answer
81 views
divide a network into 2 unequivalent subnetworks [closed]
I have two /16 networks which I want to divide : 10.84.0.0/16 and 10.94.0.0/16. I divided the first one in 4 equal subnets /18. But for the second I want a quarter of it in the first subnet, and all ...
1
vote
1answer
40 views
Packet Tracer help, dropped packets and connectivity issues
I have set up a network with 3 offices on 3 different subnets.
File available at,
https://github.com/turntheairblue/packetTracer
Router configuration is as follows,
R1 - Router
R2 - Router
R3 - ...
0
votes
4answers
109 views
How does the router tell if a packet is sent to local host or public host
I might sound silly, but I'm beginner.
If there are two hosts with the same IP but one is public and the other is private.
If I send a packet to that IP. Will it be forwarded to the local host on my ...
0
votes
2answers
107 views
Does the same IP cause IP conflict if one is from /22 other is from /24?
I have two hosts. They both have the same IP/subnet, ex.: 1.2.3.4/24 on both.
I know this is bad, since there will be duplicate IP in the network. OK.
But: If I have different (?) ranges:
1.2.3.4/...
0
votes
0answers
46 views
How To: SonicWall - New Subnet, Synology Fileserver connected X2, Accessable from LAN(X0) and SSL VPN
I have some specific Questions, because I cant figure out how the SonicWall works. To excuse me beforehand: I am not a SysAdmin but I need to configure the SonicWall properly. (Like thrown into the ...
3
votes
2answers
117 views
BGP vs OSPF path selection with /24 vs /23`
would a network select /24 or /23 path with ospf or with BGP which one is preferred !!
1
vote
3answers
136 views
Use of /30 instead of /31
Besides wasting IP addresses. Is there any other compelling reason to use a /31 subnet over a /30 on Point to Point links?
I am interested from a security perspective mainly. Would a /31 be more ...
0
votes
1answer
134 views
How can all devices connected to the router be in the same subnet? [closed]
I have understood that router is a networking device, used to connect multiple subnets. And it does the job of routing the packets from one subnet to another subnet. As depicted in the below topology-
...
4
votes
4answers
581 views
Are private IP addresses the outcome of subnetting a public IP address?
I understand the purpose of both but just verifying if this correlates together at all.
4
votes
1answer
355 views
CIDR notation and subnets
I've been given a script that will create a virtual network with the following IP range (in Azure): 10.0.0.0/16.
The script then goes on to create two subnets within that network with the following ...
0
votes
2answers
84 views
Overlapping IP addresses in CISCO 3650
I have overlapping also, but, my config is different.
Vlan 1 is 192.168.0.36/255.255.0.0 and Vlan 2 is 192.168.11.15/255.255.0.0.
Since the third octet is different, how is overlapping possible?
0
votes
2answers
90 views
Subnet IP addresses from ISP multiple times?
I am new to networking. I was wondering if it is possible to subnet an IP from my ISP multiple times with different netmasks.
For example, if I was given the IP block 141.13.0.0/16. Can I subnet this ...
1
vote
1answer
87 views
Assigning IP addresses in a Frame Relay network
I know one can design a network that connects several IP subnets with Frame Relay. I've come across two main configurations.
Full mesh:
Every router is connected with every other. Thus, I believe ...
3
votes
1answer
114 views
Change of IP address range
As part of a corporate project, I am responsible for changing the IP address range of remote sites.
I will show you a theoretical scheme of the network and explain the details of the migration.
My ...
