Category Archives: DCI

data center interconnection

37 – DCI is dead, long live to DCI

Some may find the title a bit strange, but, actually, it’s not 100% wrong. It just depends on what the acronym “DCI” stands for. And, actually, a new definition for DCI may come shortly, disrupting the way we used to … Continue reading

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36 – New White Paper that describes OTV to interconnect Multiple VXLAN EVPN Fabrics

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

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36 – VXLAN EVPN Multi-Fabrics – Path Optimisation (part 5)

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

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36 – VXLAN EVPN Multi-Fabrics – Host Mobility (part 4)

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

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36 – VXLAN EVPN Multi-Fabrics with Anycast L3 gateway (part 3)

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

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36 – VXLAN EVPN Multi-Fabrics with External Routing Block (part 2)

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

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36 – VXLAN EVPN Multi-Fabrics Design Considerations (part 1)

Notices With my friend and respectful colleague Max Ardica, we have tested and qualified the current solution to interconnect multiple VXLAN EVPN fabrics. We have elaborated this technical support to clarify the network design requirements when the function Layer 3 Anycast gateways is distributed among … Continue reading

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35 – East-West Endpoint localization with LISP IGP Assist

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

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34 – VXLAN EVPN Q-in-VNI and EFP for Hosting Providers

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

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33 – Cisco ACI Multipod

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

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32 – VXLAN Multipod stretched across geographically dispersed datacenters

VXLAN Multipod geographically dispersed VXLAN Multipod Overview This article focuses on the single VXLAN Multipod Fabric stretched across multiple locations as mentioned in the previous post 31 through the 1st option. We have been recently working, with my friends Patrice and Max, during a couple of months, … Continue reading

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31 – Multiple approaches interconnecting VXLAN Fabrics

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

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30 – VxLAN/EVPN and Integrated Routing Bridging

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

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29 – Interconnecting two sites for a Logical Stretched Fabric: Full-Mesh or Partial-Mesh

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

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A fantastic overview of the Elastic Cloud project from Luca Relandini

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

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28 – Is VxLAN with EVPN Control Plane a DCI solution for LAN extension

VxLAN Evolution in the Context of DCI Requirements Since I posted this article “Is VxLAN a DCI solution for LAN extension ?” clarifying why Multicast-based VxLAN Flood & Learn (no Control Plane) was not suitable to offer a viable DCI … Continue reading

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27 – Bis-Bis – Stateful Firewall devices and DCI challenges – Part 1 (cont)

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

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27 – Bis – Path Optimisation with ASA cluster stretched across long distances – Part 2

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

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27 – Stateful Firewall devices and DCI challenges – Part 1

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

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26 – Bis – VxLAN VTEP GW: Software versus Hardware-based

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

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26 – Is VxLAN (Flood&Learn) a DCI solution for LAN extension ?

One of the questions that many network managers are asking is “Can I use VxLAN stretched across different locations to interconnect two or more physical DCs and form a single logical DC fabric?” The answer is that the current standard … Continue reading

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24 – Enabling FHRP filter

 Isolating Active HSRP on both sites. You have been several to ask about details on the HSRP filtering configuration as discussed in the LISP IP Mobility article (23 – LISP Mobility in a virtualized environment), so here below is a … Continue reading

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23 – LISP Mobility in a virtualized environment (update)

Note: When I talked about this solution almost a year ago, we were using alpha versions of software releases, from which some improvements and command lines have changed with last released codes. Thus I’m elaborating on this original article including … Continue reading

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22 – Which DR or DA solution do you need ?

  Having described the different components required to interconnect multiple DC to offer business continuity and disaster recovery in the previous posts, I think it may be useful to provide a series of questions that you may ask yourself to … Continue reading

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21 – Data Center Interconnect – summary

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

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20 – Locator/ID Separation Protocol (LISP)

LISP VM-Mobility:   Traditionally, an IP address uses a unique identifier assigned to a specific network entity such as physical system, virtual machine or firewall, etc. The routed WAN uses the identifier to also determine the network entity’s location in … Continue reading

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19 – vCenter, ACE and OTV – Dynamic Workload Scaling (DWS)

VCenter has the ability to manually or dynamically control system resource use and allocate workload based on the physical resources available throughout the cloud. The Cisco ACE has the ability to distribute traffic load to multiple physical or virtual servers … Continue reading

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18 – Dynamic Routing Based on the Application State.

The Cisco load balancing service module, ACE, provides real-time information about the preferred route to access a specific application or service after it has moved to a new location. The ACE continually probes the state of the applications for which … Continue reading

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17 – Intelligent Domain Name Server

The Global Site Selector (GSS) is an Intelligent Domain Name Server that distributes the user’s requests to the remote sites where the applications are active. The GSS has already been described at the beginning of this article (Global Site Load … Continue reading

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16 – Client to Server Traffic

When a user accesses an application running in a distant resource, the client must be able to use the optimal path and be dynamically redirected to the data center supporting the active application or VM. However, as explained previously, the … Continue reading

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15 – Server to Client traffic

The same function of IP localization can be applied to outbound traffic so that the responses from a server sent to an end-user can exit through its local WAN access without returning the session to the default gateway of origin. … Continue reading

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14 – Server to Server Traffic

When a server migrates from one site to another, it must return the traffic to its default gateway because its IP address schema remains the same regardless of its physical location. Since there is one IP address (or virtual IP … Continue reading

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13 – Network Service Localization and Path Optimization

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

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12 – Network and Security Service Placement

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

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11 – Storage Extension

The distance between the physical resources and the effects of VM migration must be addressed to provide business continuity and DA when managing storage extension. The maximum distance is driven by the latency supported by the framework without impacting the … Continue reading

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9 – Overlay Transport Virtualization (OTV)

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

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10 – Ethernet Virtual Connection (EVC)

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

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8 – Extended Layer 2 over Layer 3 (L2 over L3) – MPLS

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

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7 – Native Extended Layer 2

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

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6 – Layer 2 Extension

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

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5 – High Availability Cluster Requirement Versus Virtual Machine Mobility

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

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4 – Cloud Computing and Disaster Avoidance

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

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3 – Network Services for Active/Active access

  Global Site Load Balancing Services: To accelerate the disaster recovery service and the dynamic distribution of the workload between the primary and secondary data centers, Cisco provides different network services to optimize the access and the distribution of the user … Continue reading

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2 – Active/Active DC

Active-Standby versus Active-Active A Hot Standby data center can be used for application recovery or to relieve the primary data center from a heavy workload. Relieving data center resources from a heavy workload is usually referred to as Active-Active DR mode. … Continue reading

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1 – Disaster Recovery

Traditional data center interconnection architectures have supported Disaster Recovery (DR) backup solutions for many years. Disaster Recovery can be implemented in Cold Standby, Warm Standby, and Hot Standby modes. Each option offers different benefits. Cold Standby: The initial DR solutions … Continue reading

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Business Continuity

Business resilience and disaster recovery are core capabilities required of the data center IT infrastructure.  The emergence of cloud computing has put a brighter spotlight on the need to ensure that a robust resilience strategy is in place down to … Continue reading

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