From its older brother IGRP which was developed in 1980s to overcome the limitations of RIP, EIGRP was an “Enhanced” IGRP protocol. The main purpose of EIGRP was to overcome the limitations of classful networks and make EIGRP a classless routing protocol. During designing of this protocol a different convergence algorithm was used making EIGRP that “hybrid” between distance-vector and link-state routing protocols. In this post we’ll go over a basic design and setup for EIGRP, however instead of using the “classic way” let’s look at configuring EIGRP using named mode which is available in Cisco IOS starting in version 15.2
If you don’t already know, site to site VPNs can be a cost-effective way for remote sites to connect to HQ resources instead of a lease line like using MPLS or Metro-E circuits. We can instead use a standard internet connection with a static IP, this is usually cheaper than a dedicated circuit. Our next steps are purchasing a firewall for the remote site (assuming you already have one at HQ) and setup a site to site VPN connection to make the connection. Continue reading
If you ever needed to hide multiple systems behind a single IP address you would use PAT. (Port Address Translation) besides using this to connect to the internet when using an RFC 1918 address, you can configure PAT for VPN connections. The benefit is the same, hide multiple systems behind a single IP address with the advantage being you can have many systems on one side of the VPN tunnel all using that single IP.
One of the neat features of Cisco VIRL is it runs on an open platform, with OpenStack as the orchestration program running on top of an Ubuntu operating system. This gives VIRL additional flexibly by being able to run third-party VMs with KVM begin the hypervisor. In this guide I’ll walk through some of the steps I took to get Windows XP up and running in VIRL. 🙂 Continue reading
I was working with a Cisco 9372TX switch, and on it I had two 40Gbps uplinks that we where using out of the available four. Talking with our VAR because we where planning on connecting in additional equipment that only supported SFP+ interfaces. So the solution was to connect to this switch with QSFP to SFP+ adapters. Thinking this would be a simple change because we are just plugging in additional adapters on the QSFP ports we planned our maintenance window and rollback plans but I wasn’t expecting a rollback for this one 🙂 Continue reading