Genie's Tech Blog

Where knowledge has no dimensions

BGP RT Constrained Route Distribution

For Handling unnecessary processing of prefixes of RT which are not imported on the PE routers we use the feature called Route-Target Constraint. With Route Target Constraint (RTC), the RR sends only those VPN4/6 prefixes to the PE that the PE has VRF importing those specific route-targets. [More]

Multicast Service Reflection - Converting Unicast to Multicast

Hello Readers, Today, we are going to discuss about an interesting topic which is Multicast Service Reflection. Consider a situation, where in a Live Webcast that needs to be conducted and there are thousand's of people who will be viewing this webcast. Will it be feasible to send a unicast to all the webcast viewers or a multicast. We know the answer: Its Multicast. But what if from where the server from where the webcast has to be hosted has some old software and does not support Multicast. T... [More]

Inter-AS MPLS VPN - Back to Back VRF

Hello All, Today, We are going to discuss about one of the very common topics on Inter-AS MPLS VPN's i.e. Inter-AS MPLS VPNs with Back to Back VRF. We are already aware of how Intra-AS MPLS VPN's work. This has been discussed deeply in one of our previous posts (Link Below). In Inter-AS VPN, Customers connect their sites across AS boundaries. The very first and basic type of Inter-AS deployment is Back to Back VRF. In this approach, the... [More]

Rate-Based Satellite Control Protocol

Hi All, Today we will be discussing about Rate Based Satellite Control Protocol (RBSCP). RBSCP is a tunneling method designed by Cisco for wireless or long-distance delay links, such as satellite links, which are having high latency or error rates. Satellite links are generally used by companies to connect some of their remote offices to the HQ site data center. Below are the characteristics of the Satellite Links: - Large round trip time (RTT) delays (550ms typical)- Relatively high error / h... [More]

Inter-VRF Routing

Hello All, Today, I will be discussing about VRF-Lite and will also be discussing one of the designs using BGP which have been seen in real world deployments which is the Inter-VRF Routing. Lets first start by understanding what is VRF.  VRF: Virtual Router Forwarding, an IOS feature in which multiple forwarding tables are used, with the choice of which table to use is based upon additional data outside of a packet's IP header, such as the L3 input interface or an MPLS tag. VRF-Lite: An ... [More]

MPLS TE Affinity

Hello Friends, Today, i am going to have an interesting discussion on Coloring concept in MPLS TE which is actually implemented through Affinity value and mask. You must have already read in my previous posts as how MPLS TE works. Today, we will be seeing how Affinity works and what is it used for. Before we start off with Affinity, lets first discuss the MPLS TE property called Attribute-Flag. Its a 32-bit bitmap on a link that can indicate the existence of up to 32 separate properties on that... [More]

Authenticating Router With ISE As RADIUS

Hello Friends, Today, I am going to discuss about authenticating a router with a ISE (Identity Services Engine) server. ISE is a security policy management and control platform. It automates and simplifies access control and security compliance for wired, wireless, and VPN connectivity. As a quick feature update, the latest ISE 1.2 has the following capabilities: 1. Integrating with most of the leading Mobile Device Management (MDM) and Mobile Application Management (MAM) technologies. 2... [More]

Multicast VPN (mVPN)

Hello Friends, Today, I will be discussing about Multicast VPN (MVPN) in which I will be explaining how it works with an example and help you troubleshoot mVPN issues on 7600 platform. As a pre-requisite, I assume everyone understands basic multicast concepts and different PIM modes specially PIM SP (Sparce Mode) and also Multicast VPN concept. First of all we, its impotant to understand that Multicast forwarding is opposite of Unicast forwarding. Unicast is concerned about where the packet is ... [More]

MPLS TE: Auto-Tunnel Mesh Groups

Hello Friends Today, I am going to discuss about one of the interesting features on MPLS TE which is the Auto-Tunnel feature which gives us the capability to create TE tunnels automatically based on the destination list. The Auto-Tunnel feature provides automatic creation of one-hop primary TE tunnels (Auto-Tunnel Primary), and both nhop and nnhop FRR backup TE tunnels (Auto-Tunnel Backup).  Auto-Tunnel Primary and Backup can be enabled separately via CLI configuration. The Auto-Tunne... [More]