Like with the Next-Generation Data Center course, the live sessions in the Building Network Automation Solutions course include guest speakers, Q&A discussions, and solutions to sample challenges that you’ll be able to use to complete your homework assignments.
The guest speakers for the January 2016 course include:
Read more ... The goal is to help customers tackle industry-specific IoT challenges.
OFNet is a new software-defined network (SDN) emulator that offers functionality similar to the Mininet network emulator and adds some useful tools for generating traffic and monitoring OpenFlow messages and evaluating SDN controller performance.
OFNet is an open-source project that is distributed as a virtual machine (VM) image. The OFNet source code is available in the OFNet VM’s filesystem. In this post, we will use the OFNet VM provided by the OFNet developer to run SDN emulation scenarios in OFNet.
The OFNet VM image is packaged as an OVA file which can be imported into most virtual machine managers. In this case, we are using VirtualBox. You may download the OFNet VM from this link.
The OFNet VM contains a Linux system running Ubuntu 12.04 and has the VirtualBox extensions installed.
Create a new virtual machine using the OFNet VM image, start up the VM and log in. After logging in, review the available OFNet documentation and install Wireshark.
Import the OFNet.ova file into VirtualBox. Use the File → Import Appliance VirtualBx menu command or press <Ctrl-I>
. Navigate to the location where you saved the OFNet.ova file Continue reading
Reverse shell is technique when a client connects to a server and the client provides its shell to the server. Clients is typically a host hidden behind the NAT or a firewall having an access to the server but not vice versa. Thanks to a reverse shell the server controls a client's shell having an access to the client's network even the client is hidden behind the NAT. They are several methods how to create a reverse shell used depending on software available on the client. I will show how to create a reverse shell using SSH, Ncat and Bash.
Picture 1 - Network Topology
Picture 1 shows our testing topology. The client (Ubuntu Server 16.04) is located behind the NAT with the IP address 192.168.1.4/24. The server (Kubuntu 16.04) has assigned the IP address 172.17.100.7/16.
1. Reverse Shell Using SSH Reverse Tunnel
This method is based on the fact that the client has knowledge of the server SSH login credentials and vice versa. SSH server must be running on both the server and client. Client must be allowed to access server through firewall.
Client:
$ ssh -R 10000:127.0.0.1:22 [email protected]. Continue reading