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

In our organization, we have two separate groups which share share network address space and a domain. A couple of slices of /24 are allocated to my group (Application Operations,) while the rest is ...
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18 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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10answers
8k views

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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1answer
36 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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76 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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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 ...
2
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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 ...
2
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2answers
745 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
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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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 ...
2
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1answer
4k views

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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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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0answers
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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0answers
21 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 ...
2
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3answers
595 views

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 ...
2
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2answers
916 views

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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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
105 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
4k views

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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1answer
1k views

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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1answer
119 views

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: ...
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1answer
4k views

dhcpd, DISCOVER, “no free leases”

I am attempting to set up a VERY simple DHCP server. I am using Ubuntu 10.04, and I installed the "dhcp3-server" package. The server has one interface (eth0) statically set to 10.0.0.10(/21). I want ...
10
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3answers
783 views

Creative IP/subnet/dns schemes

I've only administered rather small networks (<=25 nodes). Usually I put the gateway .1, dns/proxy as .10, mail at .20, printers at .30-39 and so on and so forth. I never directly use IP addresses ...
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4answers
70 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 ...
262
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5answers
60k views

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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1answer
100 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
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 ...
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1answer
70 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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2answers
101 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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1answer
57 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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1answer
67 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 ...
18
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6answers
26k views

What are the implications of having two subnets on the same switch?

Can anyone tell me what some of the implications of having two different subnets on the same switch would be if VLANs are not being used?
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0answers
87 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
71 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
137 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
80 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 ...
2
votes
1answer
2k 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 ...
1
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2answers
39 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 ...
23
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6answers
11k views

CIDR for Dummies

I understand what CIDR is, and what it is used for, but I still can't figure out how to calculate it in my head. Can someone give a "for dummies" type explanation with examples?
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1answer
125 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 ...
0
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0answers
79 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 ...
6
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5answers
3k views

Linux Command line tool to work with netmasks / CIDR notation

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?
2
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0answers
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 ...
2
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0answers
551 views

Connectivity issues with dual NIC machine in EC2

I'm trying to get some servers set up in EC2 in a Virtual Private Cloud. To do this, I have two subnets: 10.0.42.0/24 - Public subnet 10.0.83.0/24 - Private subnet To bridge these two, I have a ...
0
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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
728 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
65 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: ...