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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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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13 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
31 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
28 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
33 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
46 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 ...
17
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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
21 views

How many subnets and hosts per subnet can I get from the network 172.22.0.0 255.255.255.224? [duplicate]

Hi I am having a bit of difficulty calculating the problem. Here is how the problem is apprached. 128 64 32 16 8 4 2 1 So I know the subnet mask in binary is 11111111.11111111.11111111.11100000 to ...
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43 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
62 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
17 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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27 views

routing subnet - can not get to all hosts

I'm trying to set up a network with routing between two different subnets via a 3rd subnet. Below is a diagram showing the setup with the two routers that run CentOS. ************ * 10.0.0.1 * // ...
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27 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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0answers
56 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
62 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
32 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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0answers
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
34 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
120 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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148 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
58 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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25 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
172 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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42 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
39 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
45 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
45 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
109 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
96 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
355 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
83 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 ...
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0answers
116 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
173 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
145 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
112 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
39 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
30 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 ...
0
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0answers
157 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
80 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
189 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
136 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
42 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 ...
0
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1answer
214 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
90 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 ...
2
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0answers
70 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 ...
0
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1answer
44 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 ...
0
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2answers
1k 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
72 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: ...
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0answers
49 views

Problem with v6 subnet routing

I have a freebsd machine connecting to my sixxs ayiya-tunnel. As I decided to implement IPv6 in our complete network and not only one interface I got myself a routed /48 from sixxs. I'll use ...