Author archive: admin

Even very well designed operating system as Red Hat without software is worth not too much. In Red Hat and CentOS we use the same tools to get the programs and keep them up to date. Let’s have a look on RPM and YUM package manager.

Spanning Tree Protocol is not a good idea especially if we take into consideration data center. Wasting of bandwith by blocking links in environement which demands the highest throughput, is not desirable. Virtual Port Channel feature sorts it out in simple and clever way.

There are 3 ways regarding authentication within IKEv1 and IKEv2. So we have,  pre shared keys, rsa-enc and rsa-sign. Each of them provides different level of security. In this article we will focus on RSA based methods and we lab them out.

Nowadays, when access layer switches have 1GB ports, increasing the number of an upstream links to the distribution layer is necessary. Let’s have a look on etherchannel feature, the way that we may achieve that and how to configure its on layer 2 and 3.

If we run any file server or backup server that require high availability and redundancy the first thing that we should think about is RAID array, especially in Linux environment, where creating and configuration is easy to make. Let’s configure simple RAID 1 mirroring with 2 hard disks from a scratch.

In linux environment if you are going to move between graphical and text modes, knowing runlevels or boot targets is fundamental. Also is important how to manipulate and modify particular targets and services that are being run with them.

Spanning Tree Protocol and its variations is responsible for elimination loops and ensuring efficiency at layer 2 . Despite was invented 30 years ago and nowadays very often between Access and Distribution layers routing is utilized, it is still good to know how works and what is responsible for. 

FlexVPN is being called “one to rule them all” and there is no exaggeration in this statement. VPN that allows you for site to site connection with the remained VPNs like VTI, DMVPN and by the way for remote access as well. Let’s break FlexVPN down  based on site to site configuration. 

During designing and implementation of wireless network you will come across on Layer 2 and 3 roaming. Both of them improve scalability of the wireless network  and simplify end user life, but work differently.

When we think AAA server we think about Radius and TACACS+ servers. The servers that are responsible for authentication, authorization and accounting. What is, what we may get of AAA server and how to use its, let’s check it on real examples.