Cisco & Meraki specialists. Across the UK.
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Cisco EVPN Tenant Segmentation

Separate tenants and applications within Cisco EVPN fabrics, with explicit route leaking, shared-service access and external connectivity.

Cisco Partner since 2009 Projects & ongoing support

Illustrative Cisco and Meraki equipment in a modern data-centre aisle
Your network. Properly considered.Design · Implementation · Support
1,000+

Devices supported
across the UK

20+

Client locations
supported

Nearly 8 Tbps

Traffic handled
at peak time

3 min

Average
response time

Average response is not a resolution time or a contractual guarantee. Support scope and response commitments are agreed for each engagement.

Cisco EVPN tenant segmentation separates workload routing and connectivity within a shared fabric while allowing explicitly approved services to cross the boundary. The design needs more than a list of VNIs. MCI Network Services develops Cisco EVPN segmentation models with clear tenant ownership, route policy and security enforcement. We help customers understand what the fabric isolates, what remains shared and how that separation will be verified after deployment.

01

Workload-led design

Start with application, compute and storage dependencies rather than the switch model.

02

Clear failure domains

Understand which links, devices and sites can fail together.

03

Operational clarity

Make fabrics, external routing and management responsibilities supportable.

Define the boundary the business actually needs

A tenant may represent a customer, application environment, business unit or other administrative domain. We establish the purpose of separation and the people authorised to approve changes. Different tenant names do not automatically imply different risk requirements, and an organisational chart is not always the best guide to a routing design.

The assessment identifies workloads, address ranges, management access and supporting services. We record which communication is required within a tenant and which must cross to another domain. The customer validates this access model before route leaking or shared-service connectivity is configured. This avoids using a broad network connection to compensate for an application requirement that has not been properly described.

Illustrative Cisco and Meraki data-centre network infrastructure
01Network infrastructure designed around the workloads it carries.
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Align routing contexts and overlay identifiers

We define the relationship between tenant VRFs, VLANs, VNIs and the EVPN routes exchanged by the fabric. Route-target policy is reviewed for the intended import and export behaviour, while other identifiers are assigned according to their actual role. A consistent allocation scheme makes configuration and future expansion easier to audit.

The design is checked against the supported scale and feature combination of the selected Cisco platform. Shared hardware resources can impose limits even when tenants are logically separate. We document those constraints and the monitoring needed to recognise pressure before it affects service. Logical isolation should not be mistaken for independent capacity or a guarantee that one tenant’s demand cannot influence shared infrastructure.

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02Fibre, switching and the physical path behind the service.

A useful starting point

Not sure where to start?

Bring the requirement. We will help you define the engineering work.

Talk to a specialist

Design shared services explicitly

DNS, identity, monitoring, backup and other common services may need controlled access from several tenants. We identify the exact prefixes and application flows required, then select supported route-leaking and security arrangements. The fact that a service is shared does not justify unrestricted access to the network in which it resides.

Overlapping addresses require particular care. A design that permits address reuse must also explain how shared services, logging and administration distinguish the tenants. Translation or other integration may be necessary, with its own operational implications. We do not introduce overlap merely because the routing technology can represent it; the customer needs a workable end-to-end service and support model.

Illustrative enterprise Cisco network rack in a modern office environment
03Enterprise switching and routing, built to be operated.

Preserve security at the fabric borders

External routing can undermine otherwise sound tenant separation if prefixes are merged or exported too broadly. We review border-leaf policy, firewall paths and the treatment of default routes. Each external connection has an owner and an authorised route set. The fabric should not become unintended transit between customers, partners or security zones.

Routing separation is one layer of control. Where inspection, application filtering or encryption is required, those functions are designed and documented separately. We avoid describing a VRF or VNI as a complete security programme. The customer receives a clear account of the controls implemented by the network and the complementary responsibilities of endpoint, application and security teams.

Illustrative Cisco and Meraki network operations centre with monitoring displays
04Visibility, monitoring and operational control.

Test intended access and deliberate isolation

Acceptance demonstrates both what works and what should remain unavailable. We select representative endpoints and approved cross-tenant services, then perform authorised negative tests against prohibited paths. The tests trace routing and policy in both directions so that a one-way block or an unexpected return route is not mistaken for complete isolation.

Failure and change scenarios are included where relevant. A tenant may be correctly separated during normal operation but exposed by a backup route or temporary migration connection. We review those paths and record the tested behaviour. Any exception has a documented owner, purpose and review condition rather than being left as an unexplained broad import policy.

Illustrative Cisco and Meraki equipment in organised data-centre racks
05Data-centre connectivity with clear physical and logical boundaries.

Keep tenant lifecycle changes controlled

Adding a tenant, moving an application or retiring a customer requires updates to routes, access rules, monitoring and documentation. We define a repeatable process and checks for residual connectivity. Configuration automation can help maintain standards, but it must use an approved source of intent and should not silently repair perceived drift without authorisation.

MCI can design segmentation for a new fabric or review an existing Cisco EVPN estate. Related work includes border leaf integration and network segmentation. Share the tenant model, required shared services and present routing boundaries to begin. The deliverable will identify supported controls, operational dependencies and the evidence needed to substantiate the intended separation.

Illustrative Cisco and Meraki equipment in a modern data-centre aisle
06Resilient infrastructure from rack to service path.

Talk to a specialist

What does your network need next?

Tell us what you are planning, changing or trying to improve. We will help define a practical next step and the engineering scope.

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