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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Running out of IP addresses

We are running out of IP addresses on our expanding network. The current range is 192.168.1.0/24. Considerations: We use an ISA server as a proxy for all web traffic, this is our current default ...
0
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2answers
374 views

Default Route Configuration by IP Range

I have a scenario where I need responses on a certain range of addresses to go out through one default route and another to go out through another but don't know how to setup the route add commands to ...
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3answers
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Packets dropped due to NAT? Firewall? Unroutable private IP addresses?

Preliminary note This question is out of academic interest. I know how to work around the limitation. I use this setup to control access from one subnet to the other on IP level which works great so I ...
3
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1answer
6k views

tcpdump filter on network and subnet mask

I'm using the following tcpdump command: tcpdump -w net75.out -s 0 host 65.207.95.222 I want to change the filter on the single host to be all addresses in the following subnet: 65.192.0.0/10 I ...
0
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1answer
112 views

Overcoming same private IP addresses, different subnets

I am preparing for migration to VMWare ESXi. Part of this involves P2V a large number of physical servers. Since a lot of our applications depend on the IP addresses to stay the same (i.e. they ...
3
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4answers
2k views

OpenVPN performance terrible to other machines on server's subnet [closed]

I'm using a "server" that is a hacked-up first generation Apple TV running Linux. I'm having a lot of trouble getting OpenVPN performance to be what I would expect with my new OpenVPN setup. The ...
3
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3answers
176 views

Building up a network structure

I have the following structure: So in this case I have two different networks. What device can handle this structure, also PoE WiFi. In this case I have two measurement system attached in the PC B ...
0
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2answers
707 views

Restrict access to website in IIS to a range of IP addresses

I'm configuring a website in IIS6 to restrict access to a customer's IP address range. I've been given their IP address (81.145.41.114) and an IP range (172.17) which I am meant to allow access to. I ...
3
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1answer
306 views

Subnet Masking in IPv6

I know within IPv4 subnet masking, the network is determined by either the 1st, 2nd or 3rd set of octets. Being there are so many more characters in IPv6, how do you determine the subnet mask?
2
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1answer
266 views

setting up 2 subnets, Windows Clients (30 nodes), Linux Server, Samba, FOG

Its my first post on serverfault and my first time to setup this kind of network, so my apologies in advance if it is not well formed. I'm planning a small (education center) network that has about ...
2
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2answers
635 views

One big subnet with all clients an issue?

Disclaimer: Network rookie, might have wrong assumptions. Got a basic subnet question that im interested in hearing your thoughts about. Subnet: 192.168.251.0/24 Address Range for servers: ...
0
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1answer
163 views

VTP Domain on 2 Subnets

Let's say you have 2 different subnets (10.100.0.0/22 and 10.100.8.0/22) in one subnet. You've set up your own VTP domain. If I want to add the 2nd subnet in that same VTP domain, would there be any ...
2
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4answers
1k views

Best way of isolating VM's to protect network?

On our network (1.0/24) we have a number of servers. One of those servers is running VMware ESX with three virtual machines which are hosting various websites and applications to the outside world. ...
1
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2answers
448 views

/32 subnets on Ethernet via DHCP

Is it possible to assign to an ethernet host via DHCP a subnet mask of only the host itself, e.g. 192.168.1.123/32? Do common operating systems support this kind of configuration? I'd like for the ...
1
vote
2answers
172 views

Subnetting IPv6 addresses/routes

I would like to subnet the default IPv6 route into 2 network routes. The original default route was: default via fe80::218:74ff:fe27:9640 dev eth0 proto kernel metric 1024 I tried adding the ...
0
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2answers
153 views

What is the best IP/Subnet set up strategy for a multi-server webhosting setup?

Sorry for the mixed-up title, but let me try to explain better: We run a hosting solution, which until now has supported shared hosting and VPSes. Easy enough. We are now getting larger clients ...
0
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1answer
128 views

VPN tunnel, different subnet for all users?

We have a VPN setup for each of our three branches. I understand that each router should be on a different subnet to the router that it's connecting to, but do the routers need to be on a different ...
2
votes
2answers
4k views

Routing between subnets with one router?

I have a Draytek Vigor 2820 which is connected to three gigabit Netgear Layer 2 switches. Currently the network is fairly simple, 192.168.1.0/24. One the network I have 7 servers, around 50 ...
0
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1answer
240 views

How many assignable addresses are needed for a router-to-router connection?

I have an address zone (let's say 150.41.0.0/16) and I want to subnet it optimally using VLSM. I have a number of VLANs, each with a minimum number of needed addresses, and a couple of ...
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3answers
1k views

How can I find my subnet mask?

The popular answer to the question " How does Subnetting Work? " does a nice job in explaining subnets. I remember learning about the network classes back in CCNA class but that answer mentions ...
0
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2answers
203 views

Where do I learn about IP blocks and subnets? Or is there just a calculator that does it all for me? [duplicate]

Possible Duplicate: How does Subnetting Work? Amazon's elastic compute tool (among others) requires the ip block format for their command: ec2-authorize websrv -P tcp -p 80 -s ...
1
vote
3answers
1k views

Are same IP address with different submask unique? [duplicate]

Possible Duplicate: How does Subnetting Work? In a same block of IPv4 addresses, can there be same IPs with different submasks? For example, can I have this: 180.70.65.140/26 ...
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3answers
406 views

5 IP Addresses on a multi-homed NIC, 4 ping-able, what's wrong with the 5th?

Dell Server, broadcom NIC, 5 IP addresses all on the same subnet. Let's say 100.100.63.67-71. Windows Server 2003. From another system on the 100.100.63.* subnet, I can ping all IP addresses no ...
2
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1answer
101 views

SharePoint 2003 Site Can't be Seen Across Subnets

I apologize if this is a basic question. I've inherited a SharePoint 2003 server that has, apparently, always had this issue and I'm not all that familiar with the inner-workings of SharePoint. Some ...
0
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1answer
138 views

How does this picture get broadcast address and the usable host addresses? [duplicate]

Possible Duplicate: How does Subnetting Work? I am not really sure how did this figure example get the broadcast address and the usable host addresses.
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3answers
4k views

Finding the first and last address of a block of IP addresses with subnet mask

I am not sure if this is the right place to make this question but I thought this is one of the most appropriate SE's site to make a question on networking. Please move it to other more appropriate ...
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4answers
347 views

How do I enable an interface to hand out IPs on a certain subnet on a Cisco switch?

I have telnet access to a Cisco switch, only I need to enable an interface so it can start handing out IPs on a certain subnet. What commands do I need to use to get to the interface config file or ...
2
votes
1answer
60 views

Recommissioning subnet, accommodating device with static IP address and unknown hostname in Windows network

My company recently bought an asset management appliance (a Dell Kace M300). The setup is supposed to be pretty painless; you essentially just attach an ethernet cable, power it on, and resolve a ...
3
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3answers
217 views

Subnetting Challenges

I am trying to plan out a network with the following requirements and am having problems trying to complete a subnet plan for my network. The network consists of 3 routers that connect 3 different ...
0
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2answers
1k views

Enabling Samba Shares Across Subnets

I was curious how I could go about setting up SAMBA so that shares could be seen and used across different subnets. We have some Linux devices that are bound to Active Directory and we would like to ...
1
vote
1answer
818 views

Linux route to different subnet

Bit confused over how to handle a likely simple routing issue. I VPN into my Cisco ASA on 10.1.x.x subnet. Now, I would like to not only interact with private 10.1.x.x, but also with dmz on ...
0
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2answers
3k views

VMware vSphere 5.0 - can't configure host on multiple subnets

Is there an easy way to allow a single vSphere 5.0 host communicate on multiple subnets and allow VMs hosted there to communicate on those subnets? I've got a small farm of vSphere 5.0 that are ...
2
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1answer
239 views

ARP discovery on multiple subnets

I have an unmanaged switch which serves traffic belonging to different subnets. Lets say these are the subnets: 192.168.0.0/24 192.168.1.0/24 192.168.2.0/24 And few more subnets which I am not aware ...
2
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1answer
766 views

How can I get connected to a network printer in a different subnet with Windows 7 Professional?

So we have a mixed node set on our network with Win XP Pro, Win 7 Pro, Ubuntu 11.04, Win 2k3 Server Std, etc all within in an Active Directory Environment. We also have network printers that are ...
0
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1answer
317 views

RRAS VPN Issues - Windows Server 2008 R2

I'm trying to setup a VPN on a new Windows Server 2008 R2 box that is running Hyper-V. I have setup the VPN using the RRAS and can connect to this VPN from my PC - however I can't access any ...
1
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1answer
216 views

Openvpn: iroute for all theoretically reachable [public] IPs

I am testing the creation of an enforced default route of only public IPv4 space via OpenVPN. OpenVPN does not support 'iroute 0.0.0.0 0.0.0.0' out of the box, because it contains code that rejects ...
4
votes
4answers
2k views

Maximum Number of Hosts per Network

I recall reading this in some (I think) Cisco documentation years ago, but can't find it or any other reference to this recommendation. Anyone know what I'm talking about? Anyone still follow these ...
2
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1answer
147 views

Issues changing netmask from /24 to /22 on local network

We currently have a network, 192.168.1.0/24. We are close to being out of numbers. If we change the netmask on our servers to /22 (255.255.252.0) all equipment (hosts) with 192.168.1.xx/24 will still ...
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3answers
2k views

Windows 2008 R2 DHCP for two scope on two interfaces

I'm setting up a brand new DHCP Server over Windows 2008 R2 Standard edition server, and I'm planning to serv two differents lan with this one. Here is my configuration: 1 AD/DNS/DHCP Server with ...
0
votes
1answer
236 views

How to change my domain from 192.168.1.0/24 to 192.168.21.0/24

We are about to start using hosting service for the software we use and they've asked us to change it. I'm sure I can figure out how to change the DHCP scope, but that's not what I'm worried about. ...
0
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6answers
6k views

Advice for configuring a SonicWALL NSA 2400 to use two subnets and L2 Bridge Mode

This post is not an exact duplicate of How to configure remote access to multiple subnets behind a SonicWALL NSA 2400 . However, I am having this problem, almost verbatim. Unfortunately, we even have ...
0
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2answers
3k views

How to join 2 different subnets in one domain

I have a DC win 2008 with ip 10.0.2.x. I also have another group ( workgroup) of pc's in a remote site with ip 10.0.1.x. The two sites are connected via vpn with zyxel routers. I would like to know ...
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votes
1answer
104 views

Problem regarding sub-netting and sub-net mask [duplicate]

Possible Duplicate: How does Subnetting Work? An organization is allocated the IP block of 172.16.0.0/16. It has a head office and three branches each of which can have 500 to 4000 hosts. ...
2
votes
6answers
4k views

Find device with static IP on different subnet

I bought an used Lantronix Spider and I cant seem to see it on my network (from my routers dhcp table). So my idea is that the device is not configured to use DHCP and assigned a static IP instead ... ...
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2answers
153 views

How to find the subnet for a single IP?

I have always used the subnet tools on the web when our datacenters provide us with new ip blocks for our machines. However, I recently ordered more IPs from our European DC and they apparently just ...
9
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3answers
655 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 ...
0
votes
1answer
85 views

Subnetting help and confusion [duplicate]

Possible Duplicate: How does Subnetting Work? I am a bit confused, I have been given an address 132.132.0.0/16 and i have to devise a scheme allowing for at least 396 subnets. I think i ...
0
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1answer
617 views

How to change Hyper-V VM network settings via WMI?

I am not sure where to post this question whether at programmers.stackoverflow.com or here. So please forgive this if i am at the wrong place. My question is: How to set Subnet Mask , DNS address ...
0
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3answers
1k views

Ubuntu 10.04: Two interfaces on a same subnet with a same gateway

My ISP has given me a 187.x.x.224/29 subnet. The gateway is 187.x.x.225 I have a Ubuntu server with 6 ethernet ports. The server does NAT routing and also acts as a webserver. My plan is to have eth1 ...
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3answers
2k views

How many subnets can I create (max) inside of the network 192.168.123.X/26? And why? [duplicate]

We discuss that topic but we have too different interpretations. That is why I'd like to know how to resolve this issue. What is the truth? Can I define max 64 subnets or max 4? Writing down an ...