Networking refers to the technologies and techniques that enable the interconnection of devices and applications allowing them to communicate electronically.

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1answer
53 views

3 NICs in VMware ESX 5.5.0 cannot connect to each other [closed]

I have a Vmware ESXi 5.5.0 hypervisor, installed on a desktop pc with 3 physical NICs. The first NIC is connected to the internet (WAN), the 2nd and 3rd NICs have Access Points installed (plugged in) ...
1
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2answers
90 views

Test port reachability from a remote host even though the port is not bound to a service?

I need to check whether a remote host is able to reach a specific port. At the time of test the service bound to that port will be down. The possible issues that the test would address would be : ...
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2answers
60 views

Why can my servers not access their own addresses? [duplicate]

I have two VMs on CentOS 6.5, running Plesk 12, and the webserver is Apache 2.2. One is a clone of the other, and I inherited them setup by someone else. My problem is that I can access my sites ...
0
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1answer
444 views

Xen: can't get Dom0 and the DomUs to ping eachother

We have installed a Xen (4.1) configuration and can't get Dom0 and the DomUs to communicate (ping eachother). The DomUs are able to ping eachother but not Dom0, and Dom0 cannot ping the DomUs. We ...
0
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0answers
197 views

base filtering engine fails to start - error 5 access denied. Server 2008 R2

We had a major server fault over the weekend where some hard drives and the mainboard's raid controller failed. Mainboard and HDD's replaced - the Windows Server 2008 R2 is loading up, but many of the ...
0
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1answer
46 views

iptables not allowing ssh

This is my iptable configuration. But I cannot connect with ssh with these rules. What am I doing wrong? I want to block all traffic except ssh coming from x.x.x.x ip address. iptables -F iptables -X ...
3
votes
1answer
67 views

Cisco CVE-2014-0224 Vulnerability

We have a Cisco RV-042 Small Business router and our PCI scans flagged it as being vulnerable to CVE-2014-0224 (CCS Injection/Man-in-the-Middle). It appears to be another OpenSSL vulnerability. We ...
3
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4answers
149 views

Remove IP with ip command in linux

If I add two IPs like this: ip addr add 1.1.1.1/24 dev eth2 ip addr add 1.1.1.2/24 dev eth2 and then I try to delete one of like this: ip addr del 1.1.1.2/24 dev eth2 BOTH IPs will be deleted ...
3
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2answers
92 views

Can PoE kill unmanaged switches?

Two simple unmanaged switches have died in the same cabinet in two years, one at 18 months and one just today at six months. Both times we gradually experienced increasing intermittent verified ...
0
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2answers
95 views

Forwarding HTTPs requests to another webserver

I have an Ubuntu 12.04 Server connected to two subnets. Eth0 is 20.20.20.1, it hosts an Apache Web Server on port 80. Eth1 is dynamic IP address in 10.10.10.0 subnet. This server is not a gateway ...
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votes
1answer
36 views

can same private IP will communicate? [closed]

Suppose Company A's Lan's network address is 192.168.10.0/24 and B's LAN network's address is 192.168.10./24. when company A brought company B..then as usual they also need to make communication ...
0
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1answer
37 views

tomcat-webapp not accessible via port after windows-update

we are running 4 Virtual Machines on a MS HyperV Host. On one of the VMs (192.168.50.15) we have multiple Tomcat-Webapps on separate ports - 9010: Jenkins - 9020: Atlassian Jira - 9030: Wiki .. ...
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votes
3answers
49 views

understanding resolv.conf nameserver through system calls [closed]

I am trying to understand how /etc/resolv.conf /etc/nsswitch.conf exactly works and what is significance of nameserver entry 127.0.1.1 I did strace ping google.com to get to know about the system ...
0
votes
2answers
714 views

Optional 'network' statements in kickstart file?

I have a kickstart file which I want to use for machines with different numbers of network interfaces. When I have a KS file with multiple network clauses for multiple interfaces, anaconda refuses to ...
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votes
2answers
51 views

How to force the network machines to get the ip from a DHCP server? [closed]

How can I force all the network machines to get the IP from the DHCP server and prevent them from manually editing the network configuration. There are both Linux and Windows machines. The DHCP server ...
0
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0answers
44 views

Why is the first of two post-up commands for routing in interfaces configuration not automatically processed

We managed to connect our servers to two distinct networks and everything works fine. We use routing rules that ensure that server responds to the right network. I followed the instructions under ...
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2answers
49 views

is it possible to have Web server and NAS on the same hardware microsever? [closed]

I have a HP microserver proliant gen 8, and i want to know if there's a way to make this hardware work as NAS with freeNAS ... etc, and in the same time make it work as a web server with Centos Nginx ...
0
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1answer
589 views

BIND failing to resolve with 'WARNING: recursion requested but not available'

there are no errors in the logs and query logging won't initialize iptables is fully disabled but the server will respond with "WARNING: recursion requested but not available" because my client ...
1
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0answers
28 views

Receive many UDP packets & ksoftirqd load

I want my server to be able to handle more than 1Mpps from a 10g card. Is it possible? I have Ubuntu 14.04 with kernel 3.11 and a 16 core Xeon machine. It seems that ksoftirqd becomes bottleneck in ...
0
votes
2answers
60 views

Is there a way to find which IP I am connected to?

Let's say my eth0 interface has multiple IP addresses and I can connect with SSH to any of these. Is there a way to find out which of those I am connected to? (The background is that certain ...
2
votes
5answers
9k views

Diagnosing permission problems with Cobian Backup to network share

I'm running the latest Cobian 11. I have a Synology DS412 NAS. All of my machines (Mac and Windows) access this just fine when I'm logged in and I browse to it manually. I have Cobian installed as a ...
3
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10answers
7k 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
47 views

How can I access a Virtual Machine on different subnet? [closed]

I have two virtual machine VMachineA and VMachineB using virtual box. VMachineA (CentOs 6.5) has two network interfaces: eth0 (IP: 192.168.3.48, GW: 192.168.3.1) and eth1 (IP: 10.10.200.1). ...
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1answer
47 views

multi-wan problems with web services

I recently set up a multi-wan connection for a small company, because they are at the end of the line for any possible ISP, services do go down, and they really depend on their Internet connection. I ...
0
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1answer
108 views

Routing from VLAN to Internet via L3 Switch

Please excuse the brain-dump - trying to solve a problem that's had be running around in circles for an entire day! TL;DR - Clients on two networks separated by a L3 switch can see and ping ...
1
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2answers
35 views

Software installation by group policy

I have a server with windows 2008 r2, it is connected N client. Clients use software that releases updates. Is there an application that I install on the server, which allows you to select the ...
0
votes
1answer
91 views

Is this a botnet? [closed]

I manage networking equipment at a small ISP for 60 highrise buildings. Each building has anywhere from 1 to 60 24 port switches, or some DSLAMs, or some coax gateways, with p2p radios on the roof, ...
4
votes
2answers
508 views

Will blocking port 25 on a router cripple outlook clients?

I work at a small ISP, we manage about 60 buildings with p2p radios and a main cisco router at a central location. Recently we were notified that a phishing domain is associated with one of our IPs. ...
0
votes
1answer
57 views

How to configure a RedHat 6 server to always use the gateway?

In one of my datacenters, I need to configure the server to only speak to the gateway even if the other server is in the same network... How can I configure the network card ? I suppose something ...
1
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4answers
278 views

Software for monitoring network speed and connectivity

I have been experiencing a lot of dropped connections between on all of my devices and it is really frustrasting..... Does anyone recommend free or reasonable price software to monitor signal ...
0
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2answers
184 views

Is there any software to monitor bandwidth?

In our organization we have 3 servers that are located at the office and around 20 pc accessing the servers in the warehouse with distance between the pc and the server around 20 km (13 miles). Our ...
23
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6answers
165k views

In Windows, using the command line, how do you check if a port is open?

I want to see if traffic gets through on a specific port on another machine. Is there a simple way to test for this?
0
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2answers
155 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 ...
0
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3answers
920 views

how to enable SFTP port on the server

How can I enable sftp port on the server? When I type the following command in the command prompt, it gives the following result: C:\Documents and Settings\muralik>telnet kmkhub 22 ...
1
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1answer
45 views

UDP Proxy with cloned packets

Having UDP messages sent from dynamic public IP periodically to public IP X:20000. Need a proxy that listens in IP X:20000, then forwards duplicate/clone packets to X:20001 and a different machine ...
1
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6answers
346 views

Cannot start BIND9

I followed everything EXACTLY in this tutorial for setting up DNS. I set up everything on a blank server. However, starting BIND9 failed: rndc: connect failed: 127.0.0.1#953: connection refused I ...
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votes
1answer
52 views

Can't set up the default route from a sublan to the WAN [closed]

I am trying to connect one of my PCs to the Internet via a WiFi network using a notebook. Here is my network : (Wifi) <=============> (Notebook) <===============> (Desktop) ...
2
votes
0answers
85 views

Inconsistent data transfer throughout Ubuntu server causes system instability and data corruption [closed]

Update 2 We replaced the CPU, and all is good. It was a busted CPU! Update We replaced the motherboard, and are still getting the exact same problem. Does this mean it is a faulty CPU? What else ...
0
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0answers
25 views

Static Route Dual LAN CARD Centos 6

First let me explain the scenario. I have two internet connection (Lease LINE and BroadBand). I have a CENTOS 6 Server which is used for VOIP calling (GOAUTODIAL). Now I want everyone in the LAN to ...
0
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0answers
46 views

Dell PowerEdge 1950 - Remote Access Controller not showing in router status

I just received a Dell PowerEdge 1950 server that was pulled during a company wide IT upgrade. I got the system with blank hard drives, installed ubuntu Server on it. I am able to connect the ethernet ...
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votes
1answer
52 views

How can I connect two machine's networks using a software approach?

Updates: let's assume the locations are separated, so WAN transversal is a must, and no physical networking is possible. I want to be able to connect two machine's networks together using a ...
0
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0answers
53 views

IPFire configuration as IDS behind router

I want to use an IPFire-Server primarily as an IDS behind an already existing router. The network's router (192.168.1.1) has access to the Internet and provides LAN-Slots for the clients. There is ...
0
votes
1answer
59 views

How to assign different static IP addresses to the same machine depending on its OS on a network? [closed]

I was wondering if it is possible, e.g. to assign/reserve one static IP to a computer when it's running windows and assign a second static IP to the same computer/MAC address when it's running Linux? ...
2
votes
4answers
2k views

What could prevent one Amazon EC2 instance from pinging another instance's Private IP?

I have multiple Amazon EC2 instances which need to communicate using private IPs. However, so far I've been unable to ping one instance's private IP from another instance. I can ping external ...
3
votes
2answers
629 views

Applying outbound connection rules PER USER in Windows Firewall with Advanced Security

In the latest version of the Windows Firewall, included for example in Windows Server 2008 R2, you can block incoming connections and apply this rule only for a set of users (Users Tab in the rule ...
0
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1answer
78 views

How can I control bandwidth, access times and priority per VLAN

I'm setting up access points (TL-WA901ND) that can each support up to four SSIDs, which can be assigned to VLANs. I would like to set up three SSIDs, each on a different VLAN, with the following ...
2
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3answers
170 views

Why wget doesn't read HTTP_PROXY in uppercase format?

I know in unix/linux the enviroment variables are uppercase, like LD_LIBRARY_PATH ; HOME ; $USER and so on. Today playing with wget I saw this commands just uses lowercase enviroment variables: env | ...
7
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6answers
9k views

What's the difference between a gateway and a router?

Here we can see the router is 67.23.27.187(first hop), but the gateway is 67.23.27.1. What's the difference between a gateway and a router? How does my computer know the IP of the router when only the ...
20
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2answers
2k views

Why is my eth0 called eno16777736?

I've seen http://www.freedesktop.org/wiki/Software/systemd/PredictableNetworkInterfaceNames/, which describes the rationale for consistent/predictable device naming, and then the rules by which device ...
1
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0answers
68 views

Load Balancing over multiple ISP connections

I have been trying to implement load balance and fail over on a linux machine having multiple interfaces. Currently I am using two ISP lines and I wish to split the network traffic such that both of ...