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.

learn more… | top users | synonyms (2)

1
vote
2answers
296 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 ...
1
vote
1answer
51 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 ...
0
votes
1answer
56 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 ...
2
votes
2answers
105 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 ...
0
votes
2answers
231 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 ...
0
votes
2answers
92 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
votes
1answer
417 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 ...
0
votes
1answer
439 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 ...
2
votes
2answers
176 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 ...
1
vote
1answer
144 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 ...
0
votes
2answers
1k 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. ...
0
votes
0answers
108 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 ...
-1
votes
1answer
229 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 ...
3
votes
3answers
216 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 ...
1
vote
3answers
158 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. ...
1
vote
1answer
130 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 ...
0
votes
0answers
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 ...
0
votes
1answer
56 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 ...
0
votes
2answers
196 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 ...
0
votes
1answer
185 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 ...
-1
votes
1answer
233 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 ...
0
votes
0answers
178 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 ...
0
votes
2answers
90 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 ...
0
votes
1answer
284 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 ...
1
vote
2answers
3k 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, ...
0
votes
1answer
106 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
votes
1answer
106 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 ...
1
vote
1answer
75 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 ...
-2
votes
2answers
167 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, ...
1
vote
2answers
186 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. ...
-1
votes
1answer
92 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
votes
2answers
180 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 ...
-1
votes
1answer
58 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 ...
-1
votes
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 ...
0
votes
1answer
300 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 ...
0
votes
1answer
51 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 ...
0
votes
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. ...
0
votes
1answer
104 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 ...
2
votes
2answers
388 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 ...
1
vote
1answer
80 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. ...
0
votes
1answer
2k views

Proxmox - single public ip with multiple vms, openvz containers work, kvm's don't have a route

Currently I only have a /30 block (1 usable IP) (I just ordered a /28 for 13 usable publics, waiting) I just installed proxmox, set up a few virtual containers. Port forwarded the necessary ...
0
votes
2answers
47 views

Getting Two Networks to commincate

As a business(Business A) we recently purchased a second business(Business B) and moved them into the same building, with each business having there own separate domains\environments. Im now in the ...
1
vote
0answers
36 views

Correct name for the two reserved addresses in every subnet? [duplicate]

In the subnet 192.168.0.0/24, the IP addresses 192.168.0.0 and 192.168.0.255 are both unusable in the traditional sense, but all addresses in between are usable as expected. I understand that ...
1
vote
1answer
2k views

CentOS - IPTables - Allow nodes on subnet full access

I am using linode.com and they provide the ability to assign a private IP to each vps. What I am trying to do is setup each node's firewall to allow access from other nodes on the network, but I don't ...
2
votes
3answers
150 views

how to configure two ip blocks for use on a network

My ISP has given me a /30 and a /27 ip block I can use. for the sake of not giving out my ips I'll use 192.168.1.192/30 and 192.169.1.224/27. I'm not using a router in my setup, I only have a switch. ...
0
votes
1answer
56 views

Extend subnet with dfl-800

i have 2 locations which are connected with vpn over internet with 2 dfl-800 firewalls. Address config in firewall: Location 1 address 192.168.0.0/24. (no dhcp) Location 2 address 192.168.5.0/24. ...
1
vote
0answers
62 views

Is it worth setting up a private subnet in Amazon EC2 (VPC) [duplicate]

Amazon details how use a public + private subnet approach in VPC (http://docs.aws.amazon.com/AmazonVPC/latest/UserGuide/VPC_Scenario2.html). But, bearing in mind that Instances don't have to have ...
1
vote
2answers
182 views

IP Address shortage/Subnetting

Facing a problem where we are running out of available network addreses, we are currently on bog standard 192.168.1.x range. Reading about making more ips available and subnets and think i have just ...
0
votes
2answers
109 views

Setting exceptions to a subnet route

I have a pretty simple standard routing table on my linux box: default via 192.168.1.1 dev eth0 proto static 192.168.1.0/24 dev eth0 proto kernel scope link src 192.168.1.162 metric 1 Now I ...
0
votes
1answer
135 views

How to configure network with two routers?

Is it possible to have two routers in the public accessible subnet? ->forward all traffic for [177.x.x.{3,5,7}] Internet --- [177.x.x.1] ...