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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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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33 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
29 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
22 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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30 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
67 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
75 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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0answers
8 views

Using WLAN Router without creating new subnet [migrated]

I have the following network configuration at home I'm connected through a NanoStation M5 to the internet. The NanoStation has a DHCP server and provides IP addresses for all wired PCs which are ...
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1answer
36 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
35 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
62 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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50 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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48 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
37 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
259 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
61 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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40 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
82 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
47 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
73 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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32 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
106 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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39 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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24 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
54 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
228 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
54 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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36 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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1answer
59 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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43 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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0answers
457 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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76 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
58 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
153 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
107 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
67 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 ...
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0answers
39 views

OWPING communicating between tcp and tcp6

I am trying to deploy the perfSonar toolkit on my network. I'm testing the one-way ping tool on a local subnet, which contains the monitoring station (in this case, a laptop) and a host ( a cubox-i ...
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2answers
43 views

Clients on Local Network — simple test?

I am developing a web system for my school (it's in PHP, but that's not important). The system needs to have different behaviors depending on whether or not the user is on the school network ...
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58 views

Route public subnet to client location

Due to the fact that my ISP introduced CGN/DSLite and I still need public IPv4 addresses, I was thinking about tunneling an unused /29 that I own from my server to my local Linux box. After doing ...
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1answer
55 views

Can a site contain domain controllers from multiple domains?

For e.g. I am creating a site with 2 clients and 1 DC in it. I am setting the subnet to cover these objects. So my site say SITE1 will have 2 clients and 1 DC. So when one of these clients tries to ...
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2answers
88 views

what happens when a DC fails? How can the clients identify DC failure? [closed]

When a DC fails, it loses the privilege to authenticate and so client will find for secondary DC closest to its site. In another scenario, client has selected a DC closest to its site by using subnet ...
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154 views

VMware vSphere as gateway to internal network

I'm looking for info if it's possible for vSphere to act as gateway from my external network to an internal network. Basically: The vSphere host is on a 10.0.0.0/24 which is my "external" network. ...
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2answers
2k views

How can I use a gateway on another subnet?

I'm trying my first attempts at routing and hitting the "Network is unreachable" message. My goal is to successfully ping frome one machine (subnet 10.56.34.0) to a machine on a completely ...
2
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1answer
46 views

Sonicwall Fake network

I have a Sonicwall NSA 3500. My LAN is 192.168.0.0/16 with my Sonicwall at 192.168.11.251 I have a new device that I need to connect, it has 2 NIC cards one communicates with the network, the other ...
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1answer
87 views

VLSM subnetting (CCNA 4) [duplicate]

I do not understand the answer to this question: I thought it was like this: /24 = 126 hosts /23 = 254 hosts /22 = 510 hosts /21 = 1022 hosts Branch 4 has 850 hosts, am I missing something?? Thanks ...
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1answer
99 views

Is there a way to use Bind9 $GENERATE directive for rDNS of ranges bigger than /24?

The $GENERATE directive of bind9 makes it possible to autogenerate the reverse mapping for a range of IPs what is really helpfull for reverse dns of a dhcp range. But it seems that the $GENERATE ...
2
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1answer
1k views

Routing between 2 different subnets on 2 different interfaces in SonicOS

I'm having a bit of a problem allowing traffic between two of my subnets. Here's the structure I've built. The X0 interface has our windows server on it and it handles DHCP/DNS, etc. X1 has the WAN ...
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Are Cisco admins expected to understand classful networks?

While studying for the CCENT exam, my reference materials have made an alarming number of references to class A/B/C networks. Thankfully they just treat Class A/B/C as shorthand for /8, /16, and /24 ...
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64 views

OpenVPN identical subnets for client & server

I have an OpenVPN server (Ubuntu 14.04 routed mode) on a local network with a subnet of 192.168.0.0/24. The subnet it uses is obviously a very common subnet. My problem When a client is out and ...
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113 views

Making a reverse zone file on a 255.0.0.0 subnet

I’m trying to setup a reverse zone file for this subnet that has two hosts on it: 10.10.100.10 and 10.128.5.10. This means he netmask for the subnet would be 255.0.0.0. I inferred that the file name ...