Tag: network

Docker and Linux Networking: Custom Interfaces!

Hi All. Today my goal was to build on a previous post I wrote on Default Routing, RIP v2, and VMware Workstation NICs. The problem? I am running on AWS EC2 so nested virtualization options are lacking (Ravello Systems has

Posted in Docker, Teknocratica Tagged with: , , , , , ,

CentOS Wireless: Fix when it breaks!

Hi All – if you have ditched NetworkManager (as I have) and you are still running into wireless LAN access problems…check out this script!

Posted in Network, SysAdmin, Teknocratica Tagged with: , , , ,

OpenStack: Debugging Neutron DHCP Failures

Hi All. Today’s adventure touches on a common OpenStack Neutron theme: “I just created a VM. It’s running. It says it has an IP address. And I can’t ping it!!” Read on for how we debugged that in our lab.

Posted in Cloud, Network, OpenStack, Teknocratica Tagged with: , , ,

OpenStack: Adding External Networks to Neutron with GRE

Hello All – today’s post is on Neutron using GRE Networking. The all-in-one OpenStack gives you GRE by default but only a single external subnet. Read on to learn how to add more external networks!

Posted in Network, OpenStack, Teknocratica Tagged with: , , ,

CentOS Wireless Problems and Dumping NetworkManager

Hello All, it’s been a while since I’ve posted. This post will discuss how you can dump NetworkManager and still get your wireless to work on Linux (CentOS 6.5, specifically). Read on for more!

Posted in Network, Teknocratica Tagged with: , ,

CCNA – Don’t forget “ip routing”

Just a quick note here – if you are reading the Lammle book Chapter 7 on IP Routing, you have no doubt run into his lab with the Corp, R1, R2, and R3 routers. We did and diligently followed the

Posted in ccna, Dynagen/Dynamips, Teknocratica Tagged with: , ,

What Makes Up Networked Storage Throughput?

While researching distributed cloud storage we came up with these interesting points on storage throughput along with some great links for additional reading. Input/Output Per Second (IOPs). This is the most-commonly quoted measurement. For Amazon’s Relation Database Service (RDS) public

Posted in Network, Storage, Teknocratica Tagged with: , ,

CentOS/RHEL and wrong Network Interface

This is a quick entry on a particularly irritating CentOS peculiarity – after you clone a virtual machine, your /etc/sysconfig/network-scripts/ifcfg-eth0 no longer gets invoked. This is because CentOS can arbitrarily assign the physical network card to a different logic interface

Posted in Teknocratica Tagged with: ,

NFS via Server 2008 R2 to ESXi: The Book

This article details exactly how to take an arbitrary server, install a *hardened* Windows Server 2008 R2 (W2K8R2) image on it, and then use that W2K8R2 server to deliver NFS to ESXi hosts. We had to do this recently to

Posted in Network, Storage, Teknocratica, VMware Tagged with: , , ,

Solve “Unidentified Network Error” for Windows Server 2008

Anytime a non-routable network connection (any IPv4 network adapter that does *not* have a default gateway specified) is configured for a Windows Server 2008 server, the operating system will mark that network connection as an “Unidentified Network”. The downside? Windows

Posted in Network, Teknocratica, Windows Server Tagged with: , ,