Questions tagged [subnet]

A subnetwork, or subnet, is a logically visible subdivision of an IP network.

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93
votes
5answers
233k views

What is the difference between a VLAN and a subnet? [closed]

I have read numerous forums and articles regarding VLANs and subnets. However, I haven't understood the functions of each apart from the following: Subnets allow the segmentation of a network VLANs ...
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9answers
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Why are subnet-masks relevant for the individual computer on the network?

I understand how subnet-masks are used to divide a network into sub-networks, but, why does every computer in the network need to know the subnet-mask and not just the router? I could understand it, ...
42
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9answers
63k views

Why do we need subnet mask?

Since a IPv4 address already gives the information of the network and and host, why do we still need a subnet mask? The 1st Octet already specify the network class (1-127: A, 128-191: B, 192-223: C ...
41
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6answers
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What is a subnet mask, and the difference between a subnet mask of 255.255.255.0 and 255.0.0.0?

My DSL/WiFi router provided by my ISP has an internal IP address of 10.0.0.138, the addresses provided by DHCP are in the format of 10.0.0.xxx. Now, I want to start using static IP addresses on my ...
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4answers
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Are subnets always contiguous 1s? [duplicate]

I understand the basic premise behind subnet masks, such as 255.255.255.0. But all the subnet examples I’ve seen have been (from left-to-right) contiguous 1s (HI bits). For instance, 255.255.0.0 (/16) ...
24
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6answers
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What does it mean to have a subnet mask /32?

I see in this question, the routing table has: 192.168.1.1/32 link#4 UCS 2 0 en0 openwrt.lan 46:94:fc:63:fc:7 UHLWIir 11 3610 en0 1200 ...
22
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2answers
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What is the difference between a subnet mask and a netmask?

Is there any logic in using two different names for determining host ID and net ID? For example, if you type print route in a Command Prompt you get things with netmask, but the IPv4 settings seems ...
21
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9answers
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Why is my subnet mask 255.255.255.255?

I have a modem which used for internet broadband and I got an IP address in the 'A' class 10.x.x.x and have netmask 255.255.255.255. What does 255.255.255.255 mean exactly? When I try to sniff with ...
14
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1answer
17k views

Is there any reason to subnet a home network?

For networks I understand we set a netmask on each computer to let it know what IPs it can talk to without going through the router - IPs on the same subnet can talk directly to each other and do not ...
13
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2answers
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Communicating with devices on a different subnet

Let me start this off by saying that I am very new to how IP Address / Subnet Addresses work, and networking in general. This stuff is generally mystifying, and I've had a hard time understanding ...
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2answers
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How to create a separate subnet for wireless access?

I need to configure my wireless router so all wireless devices are on a different subnet (192.168.2.1). The wireless devices should be able to access the internet, but ideally not the workstations on ...
10
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5answers
12k views

What are the essentials of a Subnet mask?

What is the use of a subnet mask? What is the below output conveying to the user? Connection-specific DNS Suffix . : IP Address. . . . . . . . . . . . : 192.168.1.2 Subnet Mask . . . . . . . . . ...
10
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4answers
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How to put two subnets next to each other?

I've been using this calculator http://www.subnet-calculator.com/cidr.php, and I'm trying to figure out how to put two different subnets next to each other. For example, I want to have a /27 subnet ...
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3answers
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Trying to understand the interactions between two different subnets on the same network

I have a 10.0.0.0/8 network split into two parts. A DHCP server hands out addresses 10.0.0.10 to 10.0.0.150 with a class A mask (255.0.0.0). This is my “Guest” portion of the network. Authorized ...
9
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6answers
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Why is it improper network design to have two physical NICs, one machine, same subnet, same netmask, same gateway, two different IP addresses?

All I read and can see says to put two different IP addresses on one NIC. I thought if I had two NICs, I'd be better off for speed/throughput. Why is it a wrong topology to have two separate ...
9
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4answers
109k views

Why can't my OpenVPN client access machines on same LAN as OpenVPN server?

I have configured OpenVPN on my Linux server and Windows client according to the instructions here. My client can access the server, but can't get any further onto the LAN. My Server is 10.23.29.64/...
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5answers
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Can you have a class C IP address with a subnet mask of 255.255.0.0?

Can you have a class C IP address with a subnet mask of 255.255.0.0? What happens when you have a setting like this?
7
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5answers
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Why is ip address listed as 172.18.0.150/24?

Why is IP Address listed with this notation 172.18.0.150/24? I mean the ip is 172.18.0.150 only why it haves /24?, and then whatever what subnet that is on should be someone else's worries, no? 3: ...
7
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6answers
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Set up two (2) IP addresses on the same network card?

I think it is possible to set up 2 IP addresses and subnet masks on one NIC in Windows XP. How can this be done?
7
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5answers
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Where are addresses from the network 0.0.0.0/8 used in practice?

I read that this pool: Means "these hosts" in "this network" Is used for self-identification Is used for broadcast messages My questions are: Where exactly these addresses can be found? Which ...
7
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2answers
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Traceroute hops in the same subnet

in what case is there two neighbor hops in the same subnet in a traceroute output? As I know it should be only source addresses and each router interface should be in different subnet? E.g.: 1 ...
7
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1answer
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What does (Preferred), (Tentative) and (Duplicate) mean against an IPv4 Address with ipconfig

I have been tinkering with subnets and have noticed the above as annotations to the IPv4 line of ipconfig. IPv4 Address. . . . . . . . . . . : 192.168.1.241(Tentative) IPv4 Address. . . . . . . . . . ...
7
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2answers
81k views

192.168.x.x addresses with subnet 255.255.0.0

We are designing a network where we have 192.168.100.52 192.168.110.13 Initially the subnet mask was 255.255.255.0, so clearly these first two machines will not communicate with each other without ...
7
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3answers
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How do I join two subnets with two DD-WRT routers?

I have two separate DD-WRT routers which I would like to bridge together so that computers connected to each are on the same subnet (so that multicast can work between them for UPNP/DNLA media sharing)...
6
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3answers
17k views

Why subnet mask for IP 10.0.1.4 is 255.255.255.0?

Well I'm not sure whether I'm missing something here. But all I've read is that if first octet of IP is within 0 - 127 then it is categorized as Class A subnet and correspondingly Subnet Mask for ...
6
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2answers
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Is 225.225.225.128 a valid subnet mask?

I have been told that we have two devices on a network: 10.40.225.142 and 10.40.225.144 These devices both have Gateway 10.40.225.129 Subnet mask 225.225.225.128 (note 225 is Not a typo) These ...
6
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4answers
48k views

“Destination port unreachable” when pinging computer in another subnet

In my home network, I connect to the Internet through a router (192.168.1.1). I also have another router (192.168.1.15, 192.168.2.1), this one using OpenWRT, configured as a wireless client. One of my ...
6
votes
1answer
4k views

How do you route within an Amazon VPC subnet?

I have an Amazon Virtual Private Cloud that looks like this: 10.40.1.1 Internet Gateway 10.40.1.5 My OpenVPN Instance 10.40.1.100 My Windows Box What I want is traffic from the Windows box ...
5
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1answer
9k views

How to find CIDR subnet for a public Internet IP address?

Usually I do not worry about subnet of an IP address on the public Internet, but after I began using Amazon EC2 firewall, it got me thinking. EC2 firewall configuration requires an IP to be written ...
5
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2answers
36k views

how to split up network into two subnets with only one router

I have one router on my home network. This acts as the main WiFi access point for all devices, as well as being connected to a simple switch for my home lab. I would like to be able to isolate my home ...
5
votes
1answer
5k views

Home network with two routers and just one Wifi

I know it is a pretty lame question, but I am not a pro in networking, so I will still ask it. And I will try to explain details where possible. I want to create the following setup: Phone line is ...
4
votes
2answers
4k views

Windows XP doesn't like small subnets?

This totally sounds like a bug to me, because my subnet mask and IP address should be valid by all accounts. My ISP has assigned me a fixed IP address of 65.110.7.20, with a subnet mask of 255.255....
4
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3answers
11k views

I'm using Cisco Packet Tracer for Simulation and got error “ip address overlaps with..etc”

The 1st row is for my router and the 2nd row is for my LAN. What's wrong? Is my IP addressing and subnetting wrong? I already checked my configuration.
4
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2answers
1k views

How can I find any domain name that resolves to IP within a given net range?

For example, given the range: 172.128.0.0 - 172.191.255.255 I need to find some domain that resolves to an IP-adress within the range. Is it possible ? I'm using a Linux system.
4
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2answers
35k views

Lan to Wan setup how to connect two subnets

I hope someone can help me with issues I have with my home network. I have a Billion 7700N modem/router and currently I added a Western Digital N600 dual band router. By default (following setup DVD ...
4
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3answers
2k views

What is the effect or purpose of subnet on client PCs?

I understand that the subnet mask when combined with an IP is used to define the range of IPs that the router is responsible for routing. e.g. a router with 192.168.3.1 subnet 255.255.254.0, will ...
4
votes
1answer
4k views

Non-contiguous Subnet Mask

In this question: Is 225.225.225.128 a valid subnet mask? The accepted answer states that the subnet mask must be contiguous. A few comments reference RFCs stating that this is the case. However, I'...
4
votes
2answers
11k views

How do I know if two machines are on same LAN?

I am very poor with Computer Networks, even though I took class in my grad school. I keep forgetting about subnets and masks and what not! Currently, I am playing with Docker and Erlang and was ...
4
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1answer
1k views

iptables on openwrt router: logging connections to a host from clients on the same subnet

I am trying to setup an auto wake-on-lan setup using my router that is running OpenWRT 14.07, Barrier Breaker. My idea is that the router monitors any connection attempts to the host I want to wake up ...
4
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3answers
19k views

Broadcast address in IPV4

I have a small network with the subnet mask 255.255.255.240 and the IP range is 192.168.2.1 - 192.168.2.12. From 192.168.2.1, I want to broadcast a packet. I don't want this packet to go anywhere ...
4
votes
2answers
1k views

route lan traffic through wireless mifi

I have a Windows 7 laptop accessing the internet through Verizon wireless MIFI configured as 192.168.1.1. It supports only 5 wireless connections, so I don't want to use up connections unnecessarily. ...
4
votes
1answer
120 views

Active directory sites and services

I have 192.168.1.0/23 subnet for wired connection and 192.168.2.0/24 for wireless connection. Do I need to add 192.168.2.0 in AD Sites & services. Right now I have 192.168.1.0/24 added in the ...
3
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4answers
43k views

What is the diference between IP subnet mask 255.255.254 .0 … or 255.255.255.0? [closed]

What is the diference between IP subnet mask 255.255.254.0 and 255.255.255.0?
3
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2answers
13k views

Can a subnet have more than one gateway?

I am new to networking. While reading Network+ Guide Networks books, I came to Subnets but the book does not mention how many gateways a subnet can have. For example for 192.168.1.0/24 the gateway is ...
3
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4answers
16k views

How to link two routers LAN to WAN

My former modem was replaced by a all-in-one modem/router (10.1.9.1/24) after a speed upgrade. I still have my DD-WRT router (10.1.10.1/24), which I want to be my main router, i. e. as DHCP server, ...
3
votes
1answer
26k views

Communication possible between 192.168.0.x and 192.168.1.x?

I have a problem I encounter on a regular basis. I have an access point with a fixed 192.168.0.x IP address. My network is 192.168.1.x. The problem is when I plug the access point into my network, it ...
3
votes
2answers
2k views

Changing Mac OS X 10.6 Routing after VPN'd In

I have a coffee shop around the corner that I use to do some work when I want to get away from home. They offer free wi-fi and I then use my Mac 10.6 VPN to log into my work network. I have "Send all ...
3
votes
3answers
298 views

Does a typical home router support classless IP address?

All typical home routers I know of allow us to set a custom subnet mask, and because of this, I am really curious about whether they support the use of classless addressing scheme, meaning that in the ...
3
votes
1answer
10k views

OpenVPN: Route only specific subnetwork through vpn - works for single IP adresses

I was trying to route only specific subnet/single through open vpn. I have read several questions like this on superuser, and even found good answer to my question. So I am now able to route single ...
3
votes
2answers
12k views

Create private network from public wifi

My question is similar to this one, which was never answered. I live in an old apartment building that is not wired for internet access, and therefore pay a monthly fee to access an XFINITY® WiFi by ...

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