Author Archives: Yves

Good day every one, As you certainly know, we are now rebranding DCNM 11 to Nexus Dashboard Fabric Controller, consequently, NDFC 12 is the new acronym to automate and operate NX-OS based fabrics It is not just about changing the … Continue reading →

Good day everyone, I have recorded 6 different modules aimed at giving you a good understanding of the key functions that DCNM 11 offers to manage, automate and operate your data center network. While waiting for the new version 12 … Continue reading →

Refresh on Endpoint Locator in the context of DCNM The Endpoint Locator (EPL) feature allows DCNM to monitor in real-time the endpoints (EPs), the switches (location) where the EPs have been learnt, networks & VRF associated to the EPs, and … Continue reading →

Good day team, The same question arises often about how to leverage DCNM to deploy a VXLAN EVPN Multi-site between traditional Data Centers. To clarify, DCNM can definitively help interconnecting two or multiple Classical Ethernet-based DC networks, in a very … Continue reading →

Another great feature supported by DCNM 11 concerns the extension of Layer 3 network connections from a VXLAN EVPN fabric across an external Layer 3 network using VRF-Lite hand-off from the Border leaf node toward the external Edge router. There … Continue reading →

Dear Network experts, It took a while to post this update on DCNM 11.1 due to other priorities, but I should admit it’s a pity due to all the great features that came with DCNM 11.1. As mentioned in the … Continue reading →

Hot networks served chilled, DCNM style ================================================================ *** Important Note **** Since I ran the following demos using the first version of DCNM 11, a new maintenance release 11.1 came out in December 2018. As a consequence, several videos given … Continue reading →

Dear readers, Since I wrote this article last spring discussing about future integrated DCI features, VXLAN EVPN Multi-site has become real. It is available since NX-OS 7.0(3)I7(1). There is also a new White paper that discusses deeper about VXLAN EVPN … Continue reading →

Good day, In the meantime that this long series of sub-posts becomes a white paper, there is a new document available on CCO written by Lukas Krattiger that covers the Layer 2 and Layer 3 interconnection of multiple VXLAN fabrics. … Continue reading →

Ingress/Egress Traffic Path Optimization In the VXLAN Multi-fabric design discussed in this post, each data center normally represents a separate BGP autonomous system (AS) and is assigned a unique BGP autonomous system number (ASN). Three types of BGP peering are … Continue reading →

Host Mobility across Fabrics This section discusses support for host mobility when a distributed Layer 3 Anycast gateway is configured across multiple VXLAN EVPN fabrics. In this scenario, VM1 belonging to VLAN 100 (subnet_100) is hosted by H2 in fabric … Continue reading →

Notice I recommend you to read part 1 and part 2 if you missed them 🙂 Thank you, yves VXLAN EVPN Multi-Fabric with Distributed Anycast Layer 3 Gateway Layer 2 and Layer 3 DCI interconnecting multiple VXLAN EVPN Fabrics A … Continue reading →

Notice I recommend you to read part 1 if you missed it 🙂 thank you, yves VXLAN EVPN Multi-Fabric with External Active/Active Gateways The first use case is simple. Each VXLAN fabric behaves like a traditional Layer 2 network with … Continue reading →

Notices   Since this article was published 2 years ago, for 1 year we have now a integrated and hierarchical solution to interconnect multiple VXLAN EVPN fabrics called Multi-site (post 37) that offers Layer 2 and Layer 3 extension in … Continue reading →

East-West Communication Intra and Inter-sites For the following scenario, subnets are stretched across multiple locations using a Layer 2 DCI solution. There are several use cases that require LAN extension between multiple sites, such as Live migration, Health-check probing for HA … Continue reading →

Dear Network and DCI Experts ! While this post is a little bit out of the DCI focus, and assuming many of you already know Q-in-Q, the question is, are you yet familiar with Q-in-VNI? For those who are not, … Continue reading →

Since 2.0, Multipod for ACI enables provisioning a more fault tolerant fabric comprised of multiple pods with isolated control plane protocols. Also, multipod provides more flexibility with regard to the full mesh cabling between leaf and spine switches.  When leaf … Continue reading →

VXLAN Multipod geographically dispersed VXLAN Multipod Overview Note: Since I wrote this article many years ago, VXLAN EVPN and the ASIC have evolved. You should consider this article obsolete and read the post 37 (http://yves-louis.com/DCI/?p=1588) which explains why this solution … Continue reading →

As discussed in previous articles, VXLAN data plane encapsulation in conjunction with its control plane MP-BGP AF EVPN is becoming the foremost technology to support the modern network Fabric. DCI is an solution architecture that you deploy to interconnected multiple … Continue reading →

VxLAN/EVPN and Integrated Routing Bridging Summary As I mentioned in the post  28 – Is VxLAN Control Plane a DCI solution for LAN extension, VxLAN/EVPN is taking a big step forward with its Control Plane and could be used potentially … Continue reading →

This post discusses about design considerations when interconnecting two tightly coupled fabrics using dark fibers or DWDM, but not limited to Metro distances. If we think very long distances, the point-to-point links can be also established using a virtual overlay … Continue reading →

A fantastic overview of the Elastic Cloud project from Luca Relandini This post shows how the porting of the Elastic Cloud project to a different platform is achieved with UCSD http://lucarelandini.blogspot.com/2015/03/the-elastic-cloud-project-porting-to.html? And don’t miss this excellent recent post which explains how to invoke UCS Director workflows … Continue reading →

Back to the recent comments on  what is “officially” supported or not ? First of all, let’s review the different Firewall forwarding mode officially supported ASA cluster  deployed inside a single data center: Fig.1 Firewall forwarding mode within a single … Continue reading →

How can we talk about security service extension across multiple locations without elaborating on path optimisation ?  🙂 Path Optimization with ASA Cluster stretched across long Distances In the previous post, 27 – Active/Active Firewall spanned across multiple sites – … Continue reading →

Note: Since I wrote the following articles on ASA clustering stretched across multiple locations, additional improvements have been made to address some of the concerns listed in post 27.x. Please have a look at the ASA release-notes (especially 9.5(1) and 9.5(2)). … Continue reading →

Just a slight note to clarify some VxLAN deployment for an hybrid network (Intra-DC). As discussed in the previous post, with the software-based VxLAN, only one single VTEP L2 Gateway can be active for the same VxLAN instance. This means … Continue reading →

Achieving the high level of flexibility, resource availability, and transparency necessary for distributed cloud services DCI requires four components: Routing Network: The routing network offers the traditional interconnection between remote sites and gives end-users access to the services supported by … Continue reading →

The ability to avoid disasters is improved by distributing physical compute and network resources between data centers that are geographically distributed over long distances. Geographic distribution provides higher elasticity and almost unlimited flexibility of the resources required to dynamically deploy … Continue reading →

Modern firewalls, load balancers, and most stateful devices support the concept of virtual context, which is the ability to support multiple virtual firewalls or virtual load balancers. Up to 250 virtual contexts, fully autonomous and isolated from each other, can … Continue reading →

Cisco has recently introduced a new feature called OTV that extends Layer 2 traffic between multiple sites over a Layer 3 network. The edge devices that interconnect data centers are known as OTV edge devices. OTV dynamically encapsulates Layer 2 … Continue reading →

Ethernet Virtual Connection (EVC) is a Cisco carrier Ethernet equipment function dedicated to service providers and large enterprises. It provides a fine granularity to select and treat the inbound workflows known as service instances, under the same or different ports, … Continue reading →

EoMPLS For point-to-point networks across very long distances, Ethernet over Multiprotocol Label Switching (EoMPLS) Pseudowire can be useful. The EoMPLS service is supported natively on Cisco Catalyst 6500 Series Switches with the Sup720 and Sup2T cards. In conjunction with the … Continue reading →

The diversity of services required in a cloud computing environment and the constraints related to the type of applications moving over the extended network require a set of diversified DCI solutions. Cisco offers three groups of technical solutions that meet … Continue reading →

Layer 2 switching over the WAN or the metro network, whether it is a native Ethernet frame format or a Layer 2 over TCP/IP over any type of transport, should not add any latency to that imposed by the physical … Continue reading →

When a failover occurs in an HA cluster, the software components have to be restarted on the standby node. Assuming the storage has been replicated to the remote location using synchronous or asynchronous mode5, the standby node can continue to … Continue reading →

The Need for Distributed Cloud Networking If Hot Standby disaster recovery solutions running in a traditional routed DCI network are still valid and are often part of the specifications of the enterprise, there are some applications and emerging services enabled … Continue reading →