Questions tagged [subnet]

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

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why can a router make two PCs in different subnets access each other?

Case 1: PC A: 192.168.1.2 / 24, and it connects to LAN port1 of router A PC B: 192.168.2.3 / 24, and it connects to LAN port2 of router A Given above we know A and B can't talk to each other due to ...
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3 answers
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Router interface on same subnet

Could someone please explain why can't be have 2 interface on same subnet? Do router use network address to forward traffic?
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lan with multiple ip [duplicate]

If imagine lan assigned ip from from this range (192.168.1.0/24) then can we assign another ip from same subnet mask? If no why?
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2 votes
1 answer
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Can wifi clients in same subnet talk to each other without a WAP?

I understand that a L2 device like WAP is needed to forward packets from one client to another within the same network (based on MAC mostly like in 802.11) However my question is, if there is no WAP ...
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1 answer
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Must the host IP be contained in Router's subnet?

The settings are: manually set my host IP: 10.0.1.6/24, gateway: 10.0.0.138/24 they both know each other's MAC (arp -a shows the list) and there is a direct physical connection between them. From the ...
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Can an host on a subnet comunicate via an host on a segment of the subnet? and viceversa?

It's a theory only question. An host on 192.168.0.0/16 can comunicate with an host on the subnet 192.168.1.0/24 ? And viceversa? If no, why? NOTE: I already CAN calculate host, subnet, network id, ...
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Can two different LANs be part of the same private network? [duplicate]

If you had two geographically dispersed LANs with public IPs that are in a different subnet range to each other, (one is 154.30.24.x/24, and the other is 134.64.9.x/24) if they were physically or ...
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Do any subnets "Network ID" AKA "Network Address" always have an even number as the last octet? [duplicate]

Should a subnet have a "Network ID" AKA "Network Address" (eg: the first address, which is always unusable, and is the boundary between the previous subnet and the current subnet) ...
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What's the different between a "mask" in route table and interface?

if we took Windows as an example, we can use the command "netstat -rn" to show route table as follows: IPv4 Route Table ===================================================================...
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What IP addresses are appropriate for a network inside an embedded device? [closed]

I am making an embedded device with two processors, a "gateway" processor which is connected to external ethernet, and a "webServer" processor, which is only connected to the ...
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1 answer
395 views

Addresses in router's subinterfaces overlapping [duplicate]

I can't really understand why I'm getting overlapping addresses in subnets when they're between the allowed range. I have the network 192.168.1.0/24, and I have to create 3 subnets: A - 58 Hosts B - ...
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-1 votes
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How to make 2 diffrent networks in router ping each other

Hello i have this 2 routers how i can make them ping each other and alos the devices connected to them
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/8 base subnetting [duplicate]

I have a question on subnetting, the below question asks for the subnetting a /8 base network. I do not understand how to have at least 64 networks available while subnetting. I have checked the ...
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2 answers
792 views

can LAN port have multiple IP addresses of same subnet mask or different subnet mask

Can the router's ethernet interface have multiple IP's of the same subnet or different subnet mask? If yes what's the use?
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subnetting to give 4 2000 adresses [duplicate]

A large number of consecutive IP addresses are available starting at 198.16.0.0/19. Suppose that four organizations, A, B, C, and D, request 2000, 2000, 2000, and 2000 addresses, respectively, and in ...
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2 answers
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Why does ARP request not use a router instead of broadcast?

Why in ARP request does the source computer broadcast a message with the destination IP address to find the MAC address of the destination computer? Why doesn't it send the message to the default gate ...
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1 vote
1 answer
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Can a subnet use more than one default gateway address?

This follows another question i had previously asked.. I am in a situation where sub net A is connected to two routers {Router A{left}} and {routerB{right}}. The sub net A knows that the address of ...
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Two networks with two different subnetmasks

This may be a dumb question but I really don't get it. Let's assume we have two networks. Network A and B. They have the following devices: Network A Device X (IP: 192.168.0.10; subnet mask: 255.255....
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Communication between subnets on Sonicwall firewall

I have a Sonicwall TZ-350. X0 is the default LAN with IP 192.168.10.1, and X1 is the WAN. I've set up a second local subnet on X2 with IP 192.168.20.1 for a single NAS device (no switch; the device is ...
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How does RIRs actually ensure IP ranges ownership

I'm currently learning about CIDR, subnets and IPv4 classes. I understood that IPv4 classes were used to route traffic in the beginning but nowadays we use "dynamic" subnet masks with the ...
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Could someone please clarify my understanding of this question? [duplicate]

I have been asked to use a particular IP address for a homework lab. The IP address is 218.179.169.7 and I have been asked to create 24 subnets and use the 16th network address. I dont fully ...
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Divide IPv4 network into subnets in a SPECIFIC order [duplicate]

My private addresses start at 10.10.0.0/16. I must make 2 subnets with 120 and 450 starting with the 120 one and not leaving any unnecessarily unused addresses. Let me remark, it's IMPERATIVE that the ...
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Benefits of subnets in networks with externally hosted services

I'm a computer science teacher trying to understand the benefits of subnets. I understand how subnets are defined and how it can be determined using a subnet mask whether two hosts are on the same ...
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1 answer
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Why is my assignment asking me use 172.16.0.0 private addressing and IPv4 sub netted Class C address Scheme?

I am doing a project for Cybersecurity and trying to build a college campus network. The complete instructions read: LAN infrastructure layouts for all campuses. • Represent multiple building/...
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1 answer
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Connecting industrial devices to OPC server while keeping segregation [closed]

We have two industrial machines (let's call them Holding and Media) with configured network addresses 192.169.0.122 and 192.169.0.123 respectively. Currently they are isolated physically although ...
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1 answer
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directed broadcast ping on overlapping subnets

I have a router with 2 hosts connected to it. R: 192.168.0.1/24 host 1: 192.168.0.9/28 host 2: 192.168.0.15/24 Host 1's directed broadcast IP is the same as host 2, so what happens if host 1 pings 192....
3 votes
1 answer
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Recommended IPv6 prefix size for PPP to a single host?

I am using PPP to create a IPv6 connection to a remote host. What is the recommended IPv6 prefix size for a single host at the other end of the PPP connection? Should it be /128, because there is ...
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Does every link between routers demand a new subnet?

This might be a stupid question but I'm new to this. I am studying a class about basics of networking and I don't really understand one question that we have. We need to a divide the given IPv4 ...
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2 answers
364 views

Transfer subnet needed between Firewall and Routing Switch?

When looking at the image, the Switch is routing capable (L3) and is the default gateway for clients in the LAN. We plan to introduce a new Firewall and stand before the question if we should give its ...
0 votes
1 answer
134 views

In gnss3, why can't I ping my cisco router from my VM?

I have the following network, I have never configured a Cisco router before so I'm having a little trouble. In router R1 I used the following commands to assign an ip to the router: configure terminal ...
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What is the use of a host mask/ wildcard with respect to subnetting and ranges? [duplicate]

Taking the example of 10.0.0.0/20, that means my range is 10.0.0.0 to 10.0.15.255 I got that range because I know that the wild card is 0.0.15.255 and I just add it with the beginning address 10.0.0....
1 vote
1 answer
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Why does this ip address give me an error "must be valid ipv4 cidr"?

If I set up an AWS VPC with CIDR of 10.0.0.0/20 then the range is 10.0.0.0 to 10.0.15.255 I make a subnet now. Why does 10.0.15.15/28 give an error. Isn't it's range 10.0.15.15 to 10.0.15.30 which is ...
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1 answer
12k views

"Destination host unreachable" when pinging a pc from another network

I tried to build a simple network in Packet Tracer and I get "Destination host unreachable" when I try pinging a PC from another network. Pinging PCs from the same network works. When I use ...
0 votes
1 answer
213 views

Do subnets need a router between them to communicate or can multiple subnets communicate from within the same router?

Well, it's just as the question states, Do subnets need a router between them to communicate or can multiple subnets communicate from within the same router?
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How to find the first and last address in the FIRST AND LAST SUBNET [duplicate]

So there's a problem that literally stress me out every time I look at it. It's like I almost understand it until I get to knowing how to find the first and last host in the LAST address (last subnet)....
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IP address, network ID, host ID and subnet ID [duplicate]

I am studying a course about computer networking and again I stumbled upon a section that raised a question. I found very helpful people in this forum and I hope you can help me once again. During the ...
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Why does sub-netting not give us more addresses? [duplicate]

Sorry if this is dumb, but I am very knew to learning about networks. Here is my reasoning? Let's take the address, 24.50.12.4 if we subnet it with /16 then the network address is 24.50 + host is 0.0....
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1 vote
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Routing between completely separate private networks

I’ve got a request from a partner vendor in a completely separate routing domain to directly route a /24 rfc1918 network on my rfc1918 internal network. The proposed solution has their handoff ...
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difference between network address and subnet address [duplicate]

Now this question seems a bit childish to ask, but since i am new to networking, so i think i should ask the question here. while studying about subnetting, i was trying to understand a subnet mask, ...
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1 answer
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ASSIGNED or AGGREGATED-BY-LIR status of IPv6 subnet used for Virtualisation

According to the RIPE NCC IPv6 Basics training slides the ASSIGNED status should be used for your own infrastructure and individual (large) assignments to customers. The AGGREGATED-BY-LIR status ...
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Can i/how discover subnet CIDR from IP range? [duplicate]

i have found the IP range 120.76.0.0 - 120.79.255.255 that i want to ban in iptables the way i write x.x.x.x/xx format. Please how to know what that x.x.x.x/xx should be? I have found some online tool ...
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Is it possible to know the mother address of a subnet?

The mother address is X, have Y numbers of subnets (children), we already know 2 of the mother's children, they're: 10.1.192.0 /20 [edited] 10.1.240.0 /20 Is it possible to know the value of X and Y ...
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What are some techniques to infer the subnet being used? [closed]

Given a list of thousands of IPv4 addresses and that you have no direct access to these hosts, is there a service or a methodology to infer a subnet that's possibly being used?
1 vote
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Basic Subletting 10.239.142.216/11 [duplicate]

First time poster (kindly don't eat me alive) i was using https://subnetipv4.com/ to acid test my subletting skill i got 9/10 correct this is the chosen one that broke my streak as you can see i ...
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-1 votes
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different network mask and subnet mask and netmask [duplicate]

1- what is network mask? 2- what is subnet mask? is there any differnt between network mask and subnet mask? i'm tried to search about network mask and nothing found is it called netmask ? thank you
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3 answers
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32 bits or 30 bits for subnet mask

I'm new to networking and have a question about subnet masks. Imagine we have a class B IP address. I know how to calculate the subnet mask. My question is: What is the last subnet mask that we can ...
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Network topology for merging two different layer 2 networks

I have a scenario, (shown in attach diagram) where i need to merge traffic from two server 1 , 2 to target server 3. All three are on different vlans/subnets. With layer 3 switch in between would it ...
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2 votes
1 answer
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what were the classless routing protocols used with VLSM when it was first introduced?

Since VSLM is supported only by classless routing protocols, if VSLM was introduced in 1987(RFC 1009) and all classless protocol(RIPv2 developed in 1993 , OSPF standardized in 1989 RFC 1131 ) cited ...
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2 answers
295 views

Can a Subnet have more than one CIDR range?

For many years I thought of a subnet as a single contiguous range of ip addresses expressed using CIDR notation. However on GCP a subnet can have a primary ip address range from which VMs get ...
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IPs that don't have subnet mask

I'm new to networking. I know that some IPs don't have a sub net mask like 127.0.0.1 and the range that starts with 127. I wanted to know if there is any other IPs that don't have sub net mask.
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