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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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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2answers
81 views
+150

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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22 views

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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6 views

IPV6 at home: my ISP delegates me a static IPV6 /56 subnet, how can I set up an IP scheme & DHCP6 for my network? [migrated]

My network looks like this: (Cable Modem/Router) <-> (PfSense Router) <-> (Internal Hosts) The IP (changed for security) of my cable modem is: IPv6 Address ...
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1answer
37 views

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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3answers
44 views

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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1answer
34 views

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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24 views

How to configure 2 NICs on a server

Our office has a server with two NICs. We have two group at our office. Say Group A and B We have two internet connection both connected/plugged in to different switch. Both group need to access ...
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24 views

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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2answers
71 views

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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1answer
110 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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4answers
72 views

Server nics on two subnets: gateway?

Server is connected two two separate, isolated subnets via two physical nics. Is there any way the server can act as a gateway for the two networks to communicate? To clarify, I don't want any ...
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0answers
77 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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1answer
109 views

Unable to connect the Ubuntu EC2 instance to VPC LAN on AWS using secondary NIC adapter?

Infrastructure setup: VPC is created with 192.168.254.0/24 netwok Private subnet within VPC (Virtual Private Cloud) is created with 192.168.254.0/25 network Public subnet within the VPC is created ...
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1answer
73 views

pfSense: How to add a second WAN subnet for dummies

Can anyone point me to info on what to change on a pfSense device for a 2nd subnet on a single interface? My colo provider has allocated a /29 subnet to me of which I can use 3 IP addresses (for some ...
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1answer
69 views

find given subnet is overlapping in Active Directory subnet

i am looking for vb / power shell script. i need to check given subnet is overlapping with AD subnet or not. For eg. if i gave input as 192.168.2.0/24 subnet the script need to check this subnet is ...
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1answer
36 views

Online tool to calculate IP mask [closed]

I know there are so many tools to calculate a network range starting from an IP and its mask (192.168.1.0/24) but do you know an online tool to calculate the mask starting from first and last IP ...
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2answers
29 views

Could I have 2 nat on vpc [closed]

There is a vpc on amazon that has two subnets. The outer one has internet access and the inner one using NAT server to connect to internet. Inner subnet have plenty of servers for development and ...
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88 views

RRAS 2012R2 NAT with isolated subnets

I'm trying to find a solution for this problem for many weeks I hope someone can help me. I have a rather simple network: Windows Server 2012R2 with multiple NICs A few subnets (VLANs) with DHCP's ...
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2answers
72 views

Why would a public subnet be used here? [closed]

I'm a former DBA/Developer who now handles all IT aspects in a new role, more by chance than design - you know, "he used to be in IT so obviously he can handle everything" type of thing. I've set up ...
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1answer
141 views

Setting up a multi-floor wifi guest access [closed]

i just graduated from a CS bachelor so while i'm familiar with networking, i never deployed an actual "business" network before, and i was just asked to provide wifi guess access to a 16-floors ...
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1answer
81 views

Can 192.168.20.4/24 describe a network or only a host? [duplicate]

As I understand it IP 192.168.20.4/24 can only describe a host (24) on net 192.168.20.[1-254]. Now when describing a net; can 192.168.20.4/24 be a valid network ID, or should such a network ID always ...
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2answers
40 views

Different size subnets on the same system

I am working at a school campus that has 3 programs on it and has a lot of politicking involved with network administration. I am in charge of the network administration for our program along with ...
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1answer
129 views

Ports needed for IP Subnet discovery Kaspersky Security Center 10

I'm trying to discover computers based on IP subnets. The administration server is not part of the same workgroup or active-directory as the clients, so this is the only way to do it. I can ...
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80 views

How to connect from different subnets to a web server through softether vpn server

I have a web server located in a private ip say 10.5.33.2/255.255.254.0. vpn server on 10.64.1.204/255.255.254.0. it has a public ip also. I have created a virtual hub inside it and also a local ...
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62 views

Non-local IP for next hop in routing

I'm working with an MPLS network and I am slightly confused about some route entries. Interfaces are (these are fake IPs): eth0 10.10.10.1/24 (LAN) eth1 10.9.9.1/24 (MPLS) eht2 2.2.2.2/24 ...
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1answer
42 views

Trying to understand the flow of packets going from one VLAN to another [closed]

I am trying to understand the flow of the packets from one computer to the other in the same VLAN but on a different subnet as explained here. And a case shown is: Suppose the same sending ...
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2answers
738 views

Setting up a server with two NICs using two separate subnets (each on a different VLAN)

I'm using Ubuntu 14.04 (standard server install + OpenSSH, biosdevname=0 during instal to keep the network names simple) in an environment where I have two non-overlapping subnets M and N on different ...
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1answer
66 views

Are smaller subnets more efficient (when routing to/from)? [closed]

Say I have 4 IPs in a subnet. Scenario 1 (/24): Client A: 10.0.0.1/24 Client B: 10.0.0.2/24 Client C: 10.0.0.3/24 Client D: 10.0.0.4/24 Scenario 2 (/16): Client A: 10.0.1.1/16 Client B: ...
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42 views

Problem with v6 subnet routing

I have a freebsd machine connecting to my sixxs ayiya-tunnel. As I decided to implement IPv6 in our complete network and not only one interface I got myself a routed /48 from sixxs. I'll use ...
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1answer
224 views

How can I enable outgoing HTTP/HTTPS requests on an EC2 in a public subnet within a VPC on Amazon AWS

I set up a VPC using scenario 2 from the AWS Docs: http://docs.aws.amazon.com/AmazonVPC/latest/UserGuide/VPC_Scenario2.html I've assigned an Elastic IP to an EC2 instance running in a Public Subnet. ...
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1answer
63 views

Is it Possible to Capture All HTTP Packets to a Target IP on a subnet?

I've been trying to use tcpdump to capture packets to a target IP on my subnet, but am unable to do so successfully. I've tried: tcpdump -i eth0 net network-ip-address/27 -A and tcp port 80 But it ...
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1answer
124 views

Changing Network Subnet Limited User Access

Our network was originally running a 192.168.3.1 /24 network with 192.168.3.1 being the gateway on a pfSense box. We decided to increase our IP range by changing the network to a 192.168.3.1 /23 ...
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1answer
43 views

Adding static routes to remote networks

Having: My local machine (A) A remote router (B) who knows a remote network/subnet (X) My local machine's is located at the default router's (C) subnet, who know the remote router (B), but has no ...
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1answer
189 views

Network Clients receiving DHCP responses from wrong subnet

This is my first time posting and I have searched for similar question to the best of my abilities yet believe none to be helpful for my cause. My problem is, that I have a Fritz.Box 3270 as router, ...
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43 views

Deny access from from/to subnet

We are running a VPC on Amazon. Our main network is 192.168.0.0/16 We have a subnet at 192.168.1.0/24 Two subnets which are entrypoints for our VPNs at 192.168.2.0/24 and 192.168.3.0/24 And more ...
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1answer
29 views

Switching network from netmask 24 to 22

I currently have a firewall set up as x.x.1.1 and a secondary of x.x.2.1 on the firewall. On the DHCP server I have a superscope with 2 scopes handing out DHCP addresses. I was told it would be best ...
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1answer
65 views

private network with single IP multiple servers [closed]

I am trying to set up a subnet in our company. We got several (10+) Linux servers for computing but we can only get 1 static IP (company policy, 10.x.x.x address). So the idea is to place a routing ...
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1answer
397 views

Adding subnet to a vsphere with single vcenter and esxi host

Let me start of by saying that I do not specialize in networking, I am in the process of adding additional VMs to a testing environment and wanted some recommendations. In this case I am running a ...
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1answer
56 views

AWS - What do we mean by associating a subnet with an elastic network interface? [closed]

I'm trying to understand the meaning of this output: [user@ip-10-1-3-12 ~]$ ip route default via 10.1.3.1 dev eth0 default via 10.1.0.1 dev eth2 metric 10002 10.1.0.0/16 dev eth2 proto kernel ...
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38 views

network inbound from other subnets refused to server A, Server A can go outbound to internal networks, but not internet

I have a RHEL 6 server with 4 NICs on 192.168.2.[30-33]/24 Set with DHCP reservations via infoblox, I have checked and the MACs all match up. ifconfig shows /24 for every netmask, and the routing ...
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0answers
51 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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1answer
65 views

Strange behavior on 192.168.6.0 / 24 subnet [closed]

I have a Windows 7 computer running a camera system (Security cameras). The cameras are installed on 192.168.6.0/24 subnet, and I can't get the computer to connect to the 192.168.6.0/24 subnet. I have ...
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1answer
56 views

incorrent subnet/mask combination

For a network interface, I have defined a range of addresses for DHCP. 3: eth1: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc pfifo_fast state UNKNOWN qlen 1000 link/ether 08:00:27:5a:3e:be ...
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532 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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82 views

Best way to divide network?

I own a small company that recently is outgrowing our current network. Currently we have a 10.216.170.0/24 network and therefore only a limited number of available IP adresses. Now, we have a single ...
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2answers
66 views

What is this router's IP address(es)? [closed]

What is the IP address(es) of the router in my picture? In my picture, you can see that I have question marks next to the router's interfaces, because I'm not sure if those are right. Can someone ...
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1answer
211 views

Why do I lose network connectivity for a virtual machine outside /24?

I have a bunch of virtual machines (Ubuntu Server 14.04) hosted on a single real server (Ubuntu Server 14.04 with KVM). The number of virtual machines grow, and I'll soon have more than 254 of them. ...
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1answer
119 views

adding a third subnet on the same router

cisco 2800 series (isp cross connect)Eth0/0 192.x.x.x 255.255.255.252, Eth0/1 192.x.x.x 255.255.255.224 ##Eth0/1.1 192.x.x.x 255.255.255.128 <--- want to add this block in!## I've been granted ...
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1answer
86 views

Merge three DNS Servers into one [closed]

The situation is as follows: Currently three DNS servers are separated from each other, these are to be merged into one. The goal is to have only one DNS server that handles all requests of the three ...