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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Combining two subnets with same default gateway

This is the current situation: Subnet 1: 192.168.1.x (255.255.255.0) with default gateway on 192.168.1.1 Subnet 2: 192.168.90.x (255.255.255.0) without any gateway (no internet access) -> all ...
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34 views

how is a subnet mask used by a pc? [duplicate]

I understand how a router uses a subnet mask to determine whether to send a packet to the local network or to the WAN. But I am still fuzzy on how the pc uses the subnet mask. When an application on a ...
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36 views

Subnetting and VLANs for Multiple Buildings Strategy

Curious for a little feedback on how others do this. A site I'm looking at has multiple buildings connected by fiber and each is on their own subnet. 192.168.0.0 - Building 1 - VLAN10 192.168.1.0 - ...
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1answer
22 views

Locating an AWS S3 physically in a private subnet (like RDS)

Similar to how an RDS instance requires you to pick the specific subnets (which can be in a VPC's private subnet), can AWS S3 stores also be physically located in a VPC's private subnet?
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2answers
29 views

Is a “bridging device” required to join two networks?

We're considering two NBN fibre connections to the Internet (NBN is a fibre connection for those of you not living in Australia), with each connection having it's own subnet. The first connection's ...
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11 views

Can foreman handle nested subnets?

In Foreman 1.8 one can manage subnets through the web-interface at Infrastructure > Subnets. However, when I add a /24 (e.g. 10.10.0.0 with a subnetmask of 255.255.255.0), I cannot add anything less ...
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1answer
59 views

Make Asterisk to serve another subnet

I have server with Linux Ubuntu 12.04. It has two subnets - 192.168.0.1(eth0) and 192.168.1.1 (eth1). There is an Asterisk server (IP PBX) connected to first subnet, lets say it has IP address ...
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2answers
68 views

First and last IP address of the network 192.168.176.0/23 (subnet 23) [duplicate]

Let's have the following address of the network: 192.168.176.0/23. What are the first and last IP addresses of this network? Following this answer http://serverfault.com/a/327782/288201 I assume ...
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2answers
44 views

Iptables doesn't forward ssh access to instance under a public subnet

I have the following scenario: 1 - A bastion (NAT) instance which I use as a gateway to forward ssh access to all my private instances (using iptables) [Private IP: 10.10.1.10 Public IP: ...
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21 views

Security implications of wide WAN subnet

I have a server at OVH and say my public IP adress is xx.xx.xx.81 and the gateway is at xx.xx.xx.254. To reach the gateway, I need pfSense to be configured static WAN IP with xx.xx.xx.81/24, i.e. the ...
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1answer
32 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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1answer
36 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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1answer
62 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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2answers
61 views

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
1k views

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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0answers
46 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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2answers
75 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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1answer
23 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
36 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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0answers
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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61 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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2answers
72 views

What's the difference between .0/32 and .1/24 in CIDR? [closed]

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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1answer
41 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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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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0answers
42 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
147 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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0answers
242 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 ...
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1answer
60 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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0answers
31 views

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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3answers
183 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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43 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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1answer
43 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
47 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
46 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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0answers
119 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
104 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
467 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
89 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 ...
0
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0answers
123 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
179 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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2answers
182 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 ...
0
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1answer
123 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
40 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
31 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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1answer
197 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
82 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 ...
0
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1answer
206 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
146 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
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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
247 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 ...