networking - Docker : Unable to run Docker commands

I have installed docker engine v1.12.3 on Ubuntu 14.04 LTS and since after the following changes to enable Remote API, I'm not able to pull or run any of the docker images,Added DOCKER_OPTS="-H tcp://" in /etc/default/docker./etc/init.d/docker start.Following is the error received,docker: Cannot connect to the Docker daemon. Is the docker daemon running on this host?Note: I have added login in user to the docker group...Read more

networking - Simulating high latency / intermittent network connections

I'm load testing a network application using The Grinder (on a Windows PC) and I wish to simulate imperfect network conditions in order to see what effect is has on the application load, in particular I'd like to see the effect of:Variable network latency, so not only do different clients have different latency, but also latency may vary during the test for a single client.Dropped network connections - I wish to simulate what happens when a network connection is abruptly / randomly dropped.What's the easiest way of doing this?...Read more

networking - What exactly happens when we are trying to ping domain and what difference to ping to and

What exactly happens when we are trying to ping domain and what difference to ping to and when I try to ping its ping to and when ping to my website i.e its ping to, what difference in both stages.this is how ping to both domains and its take more time to ping with my siteand same, I cant browse my website with IP address how do I activate it ?...Read more

networking - Snort rule to detect a three-way handshake

I have been trying to write a rule to detect the establishment of a connection "Three way handshake" using snort IDS: alert tcp any -> any any (sid:1000; flags:S; msg:"SYN detect";)Every time i run the snort with this rule it doesn't detect the connection? is there any syntax error !! or should modify anything! appreciate the help...Read more

networking - Why do we have to use port 8001 when Port Forwarding?

I've tried to do as much research as I can around this and I can't seem to understand one thing. For my University project we were required to do the following: In VirtualBox Manager select File>Preferences. Select Network and choose NatNetwork (or the one you are using). Chose the edit network icon. Select Port Forwarding In the dialogue box provide a name for the rule (e.g. web), leave the host IP blank, provide a host port (e.g. 8001), then enter the Guest IP as the IP address of UBUNTU#1 and Guest port as 80 for a web server (answer...Read more

networking - How can i use iptables on centos 7?

I installed CentOS 7 with minimal configuration (os + dev tools). I am trying to open 80 port for httpd service, but something wrong with my iptables service ... what's wrong with it? What am I doing wrong? # ifconfig/sbin/service iptables savebash: ifconfig/sbin/service: No such file or directory# /sbin/service iptables saveThe service command supports only basic LSB actions (start, stop, restart, try-restart, reload, force-reload, status). For other actions, please try to use systemctl.# sudo service iptables statusRedirecting to /bin/systemc...Read more

networking - How can I turn either a Unix POSIX file descriptor or standard input Handle into a Socket?

In inetd and systemd type systems, it is possible for the system to bind a socket and launch the application with the socket already existing, for example to provide socket based service starting. I would like to take advantage of this functionality in one of my Haskell daemons.The daemon currently calls, socket, bindSocket, listen to create a Socket object that I can later call accept on. To change this to an inetd type system I would need to use standard input as a Socket, but all I can find so far is stdin :: Handle, or fdToHandle :: CInt -&...Read more

networking - generating network traffic with iperf without a server

I need to exercise some hardware by sending a network traffic with it. While it is doing it I will probing some of the lines with an oscilloscope. Need to verify signaling. The problem is that I won't be able to connect to any server during the test. Many reasons for that, one of each is that hardware isn't complete yet. Does anyone know if there is a away to generate network traffic with iperf without using a server? All I need is to just send some data, don't need to know if it was received. If there isn't can someone point me to a tool that ...Read more

networking - Configuring extra interfaces in wildfly swarm

I'm trying to configure an extra interface in a wildfly swarm project.The documentation says you just have to add the following snippets to the project-defaults.yml :swarm: network: interfaces: backnet: bind: this doesn't work. Does anyone know if this is actually implemented?I can add that setting the logging level to TRACE will output the generated xml configuration that shows only the default public interface and no backnet at all.EDIT: I'm working with latest "stable" swarm : 2018.1.1...Read more

In OSI Networking Model, why is Network layer above Data-link layer

I always had a feeling that in OSI, the Data-link layer and the Networking layers should switch places because overall, the layers in the model seem to move from the user specific (Application layer) towards network specific (physical layer). Now, given that MAC address in data-link layer is an artifact that is closer to the user than the network layer, I think the data-link layer should be above network layer.Now, I'm sure there is a good and logical reason for Network layer being above data-link layer; but that reasoning escapes me; can an...Read more

networking - MATLAB 7.12 R2011a Neural Network Toolbox - Does the value of net.numLayers include the input layer?

I am creating a neural network using MATLAB (version specified in title).After reading the documentation and research on the internet, I am still confused as to whether net.numLayers includes the input layer. In other words, if I want to create a 3-Layer neural network as follows: Input Layer - Hidden Layer - Output Layer should I specifynet.numLayers = 3 or net.numLayers = 2?I am confused because there is a command net.inputs{i}.range where i specifies the index on the input layer. May I remind you that i is "0" if it does not exist, otherwise...Read more