A subnetwork, or subnet, is a logically visible subdivision of an IP network. The practice of dividing a single network into two or more networks is called subnetting and the networks created are called subnetworks or subnets.

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Routing between two routers with static routes

I have a Draytek 3200 router and a pfsense rackmount router that I am trying to get to route to each other. I have a subnet on each router and a subnet for the link between, as shown here: As it ...
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26 views

Linux kernel behavior when dealing with colliding subnets

I'm using openconnect to connect to my office VPN. They push some pretty crappy/aggressive routing rules allocating ALL of the private IP address spaces >.< After I connect to my office VPN, my ...
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22 views

Utilizing A Secondary IP On A NIC In A Windows Cluster

RELEVANT INFORMATION I have a windows cluster with 3 nodes in it... Node1 Node2 Node3 I have 4 NICs on each node... NIC1_Host NIC2_Virtuals NIC3_Cluster_HB NIC4_Live_Migration This is the ...
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How to sandbox internal IPs on the same subnet with one to one NAT [on hold]

I am curious as to what technologies are employed to accomplish this with vendors that provide this service. What kind of LAN subnet restrictions can be imposed so that 2 hosts on the same internal ...
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1answer
17 views

AH00526 - apache 2.4 require ip range

I'm using FreeBSD 9.2-RELEASE-p5 w/ apache24-2.4.12 package: [root@j ~]# uname -a FreeBSD X 9.2-RELEASE-p5 FreeBSD 9.2-RELEASE-p5 #0 r265974: Wed May 14 07:57:04 PDT 2014 ...
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setting up default-gateway on a router

So I've got this weird assignment, where each branch office has to be able to access the main office (and Internet) through a serial connection. Since switches don't have a serial connections ...
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3answers
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Is it possible to SSH access a server with a misconfigured subnet?

We have a server where one of our engineers misconfigured the subnet and now we are locked out of this server and the only access that I know of would work is a serial console from IDC (it means ...
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6answers
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Linux Command line tool to work with netmasks / CIDR notation [closed]

I'm terrible at working out network subnets in my head. Is there some command line tool for linux (ubuntu packages a plus), that lets me put in 255.255.255.224 and it'll tell me that is a /27?
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42 views

Cannot Reach Secondary Subnet on Same Interface

I am running a Cisco 1841 which has an unmanaged Dell 2848 connected to it. Connected to a WIC card in the 1841 is a fiber run which goes to a subnet of devices. The primary subnet is 192.168.2.0/24, ...
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How many subnets and hosts per subnet can I get from the network 172.22.0.0 255.255.255.224? [duplicate]

Hi I am having a bit of difficulty calculating the problem. Here is how the problem is apprached. 128 64 32 16 8 4 2 1 So I know the subnet mask in binary is 11111111.11111111.11111111.11100000 to ...
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2answers
58 views

Am I meant to allocate a /64 to every host?

I have been reading conflicting sources and seeing different behaviours about how a CPE router should be assigning IPv6 addresses. RFC3633 seems to imply that each host should get /64, while RFC6204 ...
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2answers
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Sonicwall routing between multiple subnets on multiple interfaces

As shown by the network diagram below, I have two completely separate networks. One is being managed by a Sonicwall NSA 220, the other by some other router (the brand is not important). My goal is to ...
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1answer
14 views

Juniper SSG20 Additional subnet on adsl interface

I've configured a Juniper SSG20 to have some clients natted to the internet with the main ip address (X.X.27.90/30) of my IPoA ADSL connection but i have also some servers i wish to connect with a ...
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0answers
25 views

routing subnet - can not get to all hosts

I'm trying to set up a network with routing between two different subnets via a 3rd subnet. Below is a diagram showing the setup with the two routers that run CentOS. ************ * 10.0.0.1 * // ...
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2answers
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MAC OS X Server Lion - how to join two subnets?

I've got two routers connected to two different providers. I also have Mac OS X Lion server connected to both of them, so it looks like this: [INTERNET] [INTERNET] | ...
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7answers
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Advice for configuring a SonicWALL NSA 2400 to use two subnets and L2 Bridge Mode

This post is not an exact duplicate of How to configure remote access to multiple subnets behind a SonicWALL NSA 2400 . However, I am having this problem, almost verbatim. Unfortunately, we even have ...
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3answers
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Force Windows Local Subnet Traffic through a Gateway

We are attempting to route all traffic from a certain machine to a gateway. This works ok for traffic destined for subnets outside of the machine's subnet. However, traffic to machines in the same ...
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2answers
710 views

XenServer 6.2 - Hetzner host - Additional Subnet Configuration

I have a dedicated server on Hetzner, on which I have installed XenServer 6.2 . The server comes with one public IP address. I purchased an additional subnet containing 6 usable IP addresses, for use ...
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23 views

Pass multicast packets between subnets. Which static routes need to be added?

I have searched forever but cannot find a clear instruction how to set this up. I have a router providing two LANs over bridges LAN 1 on 192.168.1.0/24, bridging two access points (2.5 and 5GHz) ...
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30 views

How can you calculate IP address subnet ranges? [duplicate]

If you're given: Number of needed subnets: 2 Network Address: 195.223.50.0 I can answer the following: Address Class: C Default Subnet Mask: 255.255.255.0 Custom Subnet Mask: 255.255.255.192 ...
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55 views

Make local subnet clients get redirected like public clients, when requesting a redirected outside port on the firewall

I have a server that also functions as a firewall for the 192.168.1.0/24 subnet via iptables. It also double as a VM Server. Both the VM's and the local machines share the subnet. The servers ...
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1answer
28 views

How to use multiple IPs on dedicated server?

I have this dedicated server with /29 IPv4, and I would like to know how to use all the IPs I have avaliable. How to choose? How can I know which are the IPs? Can I use them like proxies with proxycap ...
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2answers
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What's the difference between .0/32 and .1/24 in CIDR? [on hold]

We're specifying CIDR addresses in AWS rules, and I came across something I don't understand. /32 means one single address. So 10.0.0.0/32 means only the single address 10.0.0.0. But an address ...
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15 views

IP Address Subnetting [duplicate]

For my computer networks class, I'm having a hard time understanding how to subnet IP into different networks. Here is a textbook question that I'm having difficulty on: Suppose an organization was ...
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31 views

Ubuntu Router to connect two networks via IPv6

I am currently in the situation that I want to add one network of homogenous linux nodes to an already existing windows network. For administrative reasons the linux nodes are not going to be added to ...
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1answer
111 views

connect to db instance in private VPC subnet with MySQL Workbench

How do I connect to an AWS (or other) instance in a private subnet in a VPC using MySQL Workbench ? My arrangement is a typical aws Scenario 2 : I can: - SSH into my NAT instance located in my VPC ...
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6answers
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How does IPv4 Subnetting Work?

This is a Canonical Question about IPv4 Subnets. Related: How does IPv6 subnetting work and how does it differ from IPv4 subnetting? How does Subnetting Work, and How do you do it ...
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129 views

can't connect aws VPC private instance to internet through NAT

trying to install a LAMP stack on an aws instance in a VPC private subnet using Scenario 2 described here: http://docs.aws.amazon.com/AmazonVPC/latest/UserGuide/VPC_Scenario2.html I've set everything ...
4
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3answers
169 views

Windows DNS: Is there a way to partition a domain based on subnets

In our organization, we have two separate groups which share network address space and a domain. A couple of slices of /24 are allocated to my group, while the rest is allocated to our internal IT ...
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4answers
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Are network and broadcast IPs supposed to respond?

I have a /24 network that is subnetted into a bunch of small chunks. I have recently gone into each router on the network (mostly Cisco) in order to document how this network had been divided. Now ...
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4answers
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Finding the first and last address of a block of IP addresses with subnet mask

I am not sure if this is the right place to make this question but I thought this is one of the most appropriate SE's site to make a question on networking. Please move it to other more appropriate ...
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1answer
57 views

Why do some network services require that the client and server be on the same subnet?

Periodically I run into client-server communication issues over a network, where the client cannot see the server, whereas other services don't have an issue. Many times, if I have to phone up support ...
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Windows Server spamming devices on other subnets on port 445

I have a Windows Server 2012 that every few seconds sends packets destined for port 445 on local IPs on other subnets. The IPs on other subnets it is trying to reach are devices such as VoIP phones, ...
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Route part of a subnet to a different gateway

Data network is 10.220.0.0/20 DG is 10.220.1.19 I am trying to have all traffic in 10.220.8.0 - 10.220.15.255 (10.220.8.0/21) routed to this gateway: 10.220.1.251 I can't seem to accomplish this at ...
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Use first or last free IP for the default gateway?

Please assume a simple LAN on 192.168.100.0/24. Would you configure the default router on 192.168.100.1 or 192.168.100.254 and why? Thanks
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Performance Implications to Using a Full Class A Subnet

Let's say you have a small network (50-60 IPs) and assign everything a 10.x.x.x IP with a subnet of 255.0.0.0. This gives you a huge range of usable IPs. What performance implications will this have ...
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114 views

How to setup Cisco IOS with multi public IP's

I'd like to set up a little network environment. We have bought 2 different subnet from our ISP. The WAN internet connection : xx.yy.81.61/26 WAN gateway: xx.yy.81.1 First subnet : xx.yy.81.80/30 ...
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559 views

Route two public (ISP assigned) subnets on 'outside' interface of Cisco ASA 5510

We've got a Cisco ASA 5510 that sits on our edge and acts as the PPPoE endpoint for a fibre connection. The fibre connection came with a static IP, which is assigned via PPPoE, and gets picked up by ...
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58 views

How do I prevent directed broadcast packets in Hyper-V using virtual network adapter

When I connect two physical subnets by using a Cisco Router, I can configure the router to disable directed broadcasts (that could be used for example to send Magic packets for waking up Computers ...
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2answers
940 views

Inter-VLAN routing: multiple VLANs, only one should be accessible to all. Makes sense?

I am trying to segment our company's network. My main goal is to have many small broadcast domains instead of a gigantic one, so I thought of assigning one VLAN per department. However, we have many ...
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3answers
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Must a L3 switch always have an IP address?

I have 3 L3 switches connected as shown below: All devices are in the same subnet and have IP addresses : 192.168.150.X/24 Shouldn't the switches be able to forward traffic without requiring IP ...
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2answers
2k views

Broadcast traffic on large vlan in numbers [closed]

I'm looking for the magic number of how many clients make sense to have on a single VLAN, before the broadcast traffic becomes a real issue. Preferably, I'd also like to know what a good number of ...
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1answer
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How to efficiently subnet a network [duplicate]

I have base ip address 10.6.0.0/16. I need to divide this network into 12 subnets, and I need at least 80 computers in one network. Please explain how to calculate correctly subnets. I understand that ...
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Port forwarding to different subnet

I have two routers: router A with internet access, and router B acting as wireless access point. Devices are attached to router B via ethernet. I need to forward some ports to PCs attached to router ...
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3answers
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How to access devices with static IPs on different subnet than router?

I have a SonicWall TZ100, firmware SonicOS Enhanced 5.8.1.13, with a static subnet of 10.0.6.0/24 on X0. Ports X2-X4 are port shielded to X0. On ports X3 and X4 I have two devices that were moved from ...
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2answers
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How to connect 2 networks without access to router config?

I am trying to connect 2 devices in different subnets. Device 1: IP address: 172.20.35.1 netmask: 255.255.0.0 gateway: 172.20.1.1 Device 2: IP address: 172.20.100.100 netmask: 255.255.255.0 gateway: ...
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296 views

Cannot RDP into Windows 7 over VPN

The exact scenario where it fails: I am unable to RDP into any Windows 7 or 2008 R2 servers within a certain subnet, while connected to the network via VPN. Windows 7 Client connected through the ...
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3answers
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Routing between two subnets using a Linux box with two NICs

I have a Linux box with two NICs, each connected to a different LAN: Network A: 192.168.1.0 255.255.255.0 Network B: 192.168.2.0 255.255.255.0 The routers are: 192.168.1.1 192.168.2.1 Linux NICs are ...
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Cisco, How to do a subnetting scheme using VLSM and RIP-2?

I'm studying for my CCNA exam and I have to create a VLSM scheme using RIP-2 for the following requirements: (this is an exercise) Use the class C network 192.168.1.0 network for your ...
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Trouble subnetting [duplicate]

Possible Duplicate: How does Subnetting Work? I have to learn how to subnet by hand for the CCNA exam. And I'm having real problems doing it. I keep getting stuck. Here's an example: ...