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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Some computers in my subnet do not recognize names of other pc's

I have two subnets: 192.168.0.1-255 192.168.50.1-255 Ewerything works via VPN (because physically computer from both subnets are in different locations). We also have active directory. Now, the ...
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101 views

Can I create VLANs when there are subnets already?

I need to have separate subnets in each room but at the same time, I need a few computers (spread across rooms in different subnets) to be in a single VLAN. Is it possible or do I need to rework the ...
2
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1answer
368 views

Openvpn different subnet with dynamic ip using client-config-dir (cdd)

Good Morning, I need some help for a specific configuration in a server. Let's say I have two kind of people that will connect to my VPN. Pepole from Group A and people from Group B. I need them to ...
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1answer
51 views

Delegate NS resource record of IPv4 subnet

Is it possible for a reverse zone to name another DNS server in the NS record? I want to delegate DNS for all addresses within a subnet to a site using that subnet. Our office leases a subnet which is ...
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3answers
257 views

DHCP Relay vs Multi-Homed DHCP Server

I'm sketching out a new network topology and I'm unsure of how to solve the issue of DHCP between two VLANs. 10.50.2.0/23 will hold the majority of our users, corporate wifi, printers etc. ...
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1answer
81 views

Set up Wheezy Subnets

I'm trying to create multiple subnets on a Wheezy server, where I can run multiple virtual machines off of each subnet. Initially, I'd like to create 2 and I've gotten one of the subnets working, but ...
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108 views

What are the disadvantages of re-using the same IP scope in multiple subnets? [closed]

We're designing a somewhat large system that we're not really qualified to design. It will be something like a campus: one main, large network, with about 20 sub-networks that are like departments ...
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1answer
379 views

XenServer - VMs to access Internet, but should not be visible from the Internet

I have installed XenServer on my server at the Hetzner datacenter. I have bought an additional /29 subnet containing 6 usable IP addresses from them. I want to install more than 10 VMs on this ...
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1answer
181 views

cisco firewall access rules for intra-subnet traffic

I have a Cisco 5505 in our office, and everything is on the 10.0.1.0 network. We have a cheap wireless router that we would like to use. The router is sitting behind the inside interface, and is ...
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459 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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2answers
381 views

Routing Internet traffic through computer on another subnet

Ubuntu box server has 2 network interfaces: eth0 50.57.71.100 eth1 10.182.161.100 Ubuntu box client has 1 network interface: eth0 10.177.30.100 server and client can already talk to each other ...
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73 views

Printer proxy between different subnets

I have a Xerox WC 7120 network printer on IP a.a.a.a/24. An eternal client application prints to that printer via a VPN tunnel. I will have to move that printer to a different subnet c.c.c.c/24. Is ...
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67 views

Expanding a macro containing a subnet IP address with prefix (CIDR) in a list using PF firewall

I’m trying to expand a macro that contains an address with a subnet mask into a list with PF like so: subnet1 = "192.168.1.0/24" subnet2 = "10.0.0.0/8" subnets = "{" $subnet1 $subnet2 "}" But this ...
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2answers
117 views

How to get a report of all mac addresses on another subnet?

We have an MPLS consisting of two branches: Location1 and Location2. I am using the Softperfect netscan to report all ip addresses and mac addresses of devices on Location1 where my workstation is ...
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2answers
314 views

2 WAN with separate routers, but need to be same network

My office has a 100mbps fibre internet and we connect all devices to it via a Netgear WNR3500L. I am thinking of subscribing to another 200mbps with another ISP (because the current ISP does not have ...
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2answers
94 views

Questions regarding my network plan

I'm developing an IT infrastructure room for testing purposes. The overall aim is to create a network, which if fully disconnected from the productive environment and several people can come and ...
2
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1answer
524 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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1answer
732 views

How to get 192.168.3.2 to successfully ping 192.168.2.3

With the layout described below, the following is true: either router can ping any host on either subnet 192.168.2.0/25 hosts can ping (and ssh to) 192.168.3.0/24 hosts but 192.168.3.0/24 hosts ...
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2answers
215 views

What are the security issues in creating a firewall between two subnets?

As I understand it, the hosts on different subnets cannot communicate with each other unless there is a router somewhere on both subnets that forwards traffic between them. I have have two subnets ...
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1answer
190 views

Can Windows Server 2003 DHCP Server assign multiple IP Addresses to a single host?

I have Windows 2003 Server handling DHCP for our network. We use reservations to assign some hosts IP addresses. Is it possible for the server to assign a single host two IP addresses in different ...
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2answers
2k views

Why can't I have the same subnet on WAN and LAN?

I want to know why same IP with same mask on both WAN and LAN side could be a problem. I also want to know if setting different mask, but having same IPs will resolve the routing problem. ...
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119 views

OpenVPN group clients in private subnets

I would like to group all my clients in 3 subnets: subnetA 10.0.1.0/24 subnetB 10.0.2.0/24 subnetC 10.0.3.0/24 and server at 10.0.0.1 with the following rules: clients in same subnet can reach ...
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1answer
288 views

Several logical IP subnets within single physical Ethernet broadcast domain? [closed]

I'm using Xubuntu 12.04 and Wireshark to analyse network traffic in my ISP subnet I'm wired to. My system has the following IP configuration: IP Address: 10.10.103.28 /24 Subnet Mask: 255.255.255.0 ...
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228 views

Why does operating system need to know subnet mask? [duplicate]

If I understand correctly, the operating system gets subnet mask together with IP and other stuff from the DHCP server. And this subnet mask seems to be important for router because it knows if packet ...
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3answers
181 views

Iptables subnet

I have an iptable rule where I allow a subnet of IPs. The rule is as the following: iptables -I INPUT 2 -i eth0 -s x.x.x.x/24 -d x.x.X.x -j ACCEPT For example, I want to allow subnet 172.16.0.0/24. ...
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1answer
190 views

Is it possible to send different-per-subnet DNSes from the single ISC DHCP server?

The case I want to cover is to send different DNS server for one, isolated VLAN, which purpose is to give internet-only access - for our guests. It has no access to our internal network, so it ...
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38 views

simple subnetting, regarding vpn

i am using 2 cisco rv180 to build up a ipsec tunnel. thats working. but i cant get any packets trough the tunnel. first i was using: local: 10.0.0.X 255.0.0.0 remote 10.0.1.x 255.0.0.0 but 0 ...
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58 views

Can I use a subnet to limit access to resources?

I have a somewhat limited knowledge of network configuration, but would like to achieve something like the following: have two work areas set up the "admin" work area happens to be physically ...
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2answers
234 views

Apache reverse proxy forwarding different source IP ranges to different destination URLs

There's probably an existing question (or guide somewhere on the web) about this, but I couldn't find it. We want to slowly migrate our user base from one implementation of the back end server to a ...
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1answer
213 views

How to add another router on an existing subnet? [closed]

What I am trying to do is basically this. I am on a network who's routing table is something like this. Destination Gateway Genmask Flags Metric Ref Use Iface default ...
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1answer
311 views

How to connect devices behind Comcast router/modem with devices behind wireless router [closed]

I know this is going to seem like a simple solution but I have been unable to find a clear answer through Google. Simple office setup: I have a Comcast modem/router that has 4 hard wired ports. In ...
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205 views

Routing outgoing HTTP/HTTPS traffic over a different subnet

I am trying to set up a Linux Server which was initially only supposed to be in one "server-subnet". However I am forced to use a proxy to access HTTP/HTTPS services in this subnet, which causes a lot ...
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2answers
94 views

Controlling 2 DHCP servers in one network

In my customer network, we have 2 DHCP servers. One is fully controlled by me and another by a different vendor. I want to make sure a set of devices (my devices) when connected, should get IP address ...
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1answer
316 views

Proxmox 31 + KVM routing + IP subnet + csf

We have proxmox 3.1 server in netzner with routuing network and IP subnet block. We want to implement csf firewall without interfering the traffic of the KVM VMs, what would be the easiest way? We ...
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2answers
4k views

Connecting to a remote server through a VPN when the local network subnet address conflicts with a remote network

This is a Canonical Question about solving IPv4 subnet conflicts between a VPN client's local network and one across the VPN link from it. After connecting to a remote location via OpenVPN, ...
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1answer
109 views

Adding Multiple Interfaces to EC2 Ubuntu 12.04

I have a m1.medium Ubuntu 12.04 instance with two ENI's. I have a VPC setup with a private and public subnet. Private: 10.50.1.0/24 Public: 10.50.101.0/24 I initiated the instance on the private ...
4
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1answer
112 views

why would you create two different subnets on the same physical network?

I'm working at a messy location, one of the strange (for me) things is that on the same physical network there are two different subnets. Specifically some computers will have 10.0.0.0/24 and some ...
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1answer
77 views

Name resolving issue

I have a problem with my VoIP server name not resolving by voip.companyname.com If I try to ping it from windows 7/w2k8 the request is not coming back unless I type FQDN which would by ...
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2answers
197 views

How to programmatically determine dynamic IP from behind a subnet [duplicate]

Sorry for the noob question, but I'm trying to hack together an ad hoc dynamic dns to reliably connect two machines in different geographic regions. My issue is every command I try (ifconfig, ...
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2answers
218 views

NFS mount with file locking not possible any more after move to new subnet: statd timed out, lockd cannot monitor

I'm operating an Ubuntu 10.04 NFS Server with LDAP user authentication on a virtual machine in Subnet A. The server exports the users home directories with nfs v3 to ubuntu clients in subnets B and C. ...
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1answer
100 views

Can 2 IP's in the same network communicate with 2 different netmask

I need to expand a network really quick and don't have time or access to change the netmask of all devices. Can the following communicate? IP 1 - 192.168.10.10 mask 255.255.255.0 IP 2 - ...
2
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2answers
237 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 ...
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1answer
60 views

How to integrate a separate sub-network within a customer's existing LAN? [closed]

I work for a machine builder, and our system has it's own ethernet network (192.168.1.x) with a switch and a dozen devices, most of which have firmly established static IP addresses. For our next job ...
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2answers
47 views

Configuring several subnets on a single IP [closed]

Is it possible (and correct) to configure one single IP with several subnets? For example: ip subnet 172.30.176.17 172.30.176.0/23 172.30.176.17 172.30.176.0/24 Is this a valid ...
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1answer
347 views

OpenVPN Setup with multiple AWS VPC Subnets

I have an OpenVPN server running on Ubuntu 12.04 in an AWS VPC with 3 subnets. I am able to connect my client and can ping the server (10.8.0.1) with no issues, however I cannot reach any other ...
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1answer
52 views

Class C Addressing [duplicate]

I recently saw someone use '200.1.2.0/18.' This doesn't make any sense to me. This is a Class C address with a subnet mask of /18. I thought the subnet mask for a Class C had to be at least /24. How ...
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1answer
1k views

Configure DHCPD with assigned IP address and gateway on different subnets for KVM [closed]

I have a dedi with an IP range of 123.123.123.1/24, the problem is the gateway address: 111.111.111.254 and it's on completely different subnet. I have already setup a bridge and KVM virtualization. ...
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1answer
109 views

Sonicwall Routing Subnets

I have a Sonicwall TZ105W that has a Synology NAS (10.0.0.8) on the LAN zone (10.0.2.0/24). The NAS provides a VPN service that is delegated a 10.0.2.0/24 network. How can I set up routing on the ...
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2answers
451 views

Why do all computers on my network have the same MAC address?

I'm on a LAN provided by an ISP. My computer has its IP address, Subnet Mask, Default Gateway, DNS Servers(using DHCP). I just wanted to see the MAC addresses of all the computers on my LAN. After ...
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84 views

Client doesn't get new IP when switching between subnets/locations

So here is our setup. We have 14 locations each with its own subnet and router. The routers at these locations have DHCP relay enabled that points back to our central server that is running DHCP. ...