Connect. Secure. Manage.
Cisco EVPN Overlay Design
Design the EVPN control plane and VXLAN overlay on supported Cisco platforms, including route exchange and endpoint learning behaviour.
Devices supported
across the UK
Client locations
supported
Traffic handled
at peak time
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 overlay design sets how workload networks and tenant routes use the fabric. We plan the network identifiers, endpoint data and route rules together. The design keeps these services distinct from the IP paths beneath them. It explains which apps can connect, which must stay separate and what changes when workloads move.
Workload-led design
Start with application, compute and storage dependencies rather than the switch model.
Clear failure domains
Understand which links, devices and sites can fail together.
Operational clarity
Make fabrics, external routing and management responsibilities supportable.
Establish the services the overlay must provide
We check which subnets need Layer 2 extension, where routing should occur and which tenants or apps must remain separate. Not every workload benefits from being placed in a stretched broadcast domain. The design considers whether routed boundaries can meet the need with smaller failure domains and simpler operations.
The workload model also defines mobility and growth assumptions. We ask which systems may move between hosts or racks and how their addresses and gateways are expected to behave. Those needs influence endpoint learning, distributed routing and external network access. They should be documented before identifiers and route policies are allocated, not inferred after the first migration encounters a conflict.
Standards & partnerships
Confidence in the team behind your network.
Cisco Partner
Cisco Meraki
Cyber Essentials
Cyber Essentials PlusMCI Network Services is operated by Proxar Ltd. Certifications apply to the certified legal entity and the scope of its certificates. View accreditation information
Define EVPN control-plane relationships
The overlay design specifies how the relevant BGP EVPN information is exchanged and which devices perform each role. We check the supported topology for the actual Cisco hardware and software. Route-reflector or other control-plane choices are assessed against scale and failure behaviour rather than copied from a diagram intended for a different setup.
We document the relationship between endpoint advertisements, IP prefix information and the services that consume them. Different route types have different purposes. The design uses only the functions required and supported. The operations team receives expected-state examples and troubleshooting boundaries so that a healthy BGP session is not mistaken for proof that every tenant route has been imported correctly.
A useful starting point
Not sure where to start?
Bring the requirement. We will help you define the engineering work.
Allocate identifiers and policy consistently
VLANs, VNIs, routing contexts, route distinguishers and route targets need a coherent allocation method. We explain which identifiers distinguish information and which control import or export behaviour. Confusing those roles can create missing reachability or unintended tenant network access. The allocation schedule becomes a controlled source for rollout and later expansion.
The design addresses shared services and exceptions clearly. A route target or broad import policy should not be used to make a difficult app work without reviewing the resulting access. Where route leaking is required, the permitted prefixes and security enforcement are documented separately. Routing separation is not described as encryption or as a replacement for every app security control.
Different environments. The same care.
Built around the work
your network supports.
Finance, banking and the wider private sector. We start with the systems and people that depend on your connections.
Finance & banking
Market-data paths, routing and provider coordination on clients’ behalf.
Financial-market services ↗Offices & multi-site teams
Reliable access between people, workplaces and business applications.
Office network design ↗Data centres & cloud
Network boundaries, workload connections and operational ownership.
Data centre networks ↗Align gateways, endpoints and external paths
Supported anycast gateways can provide a consistent gateway presence across the relevant attachment locations. We set out addressing and gateway identity in line with the chosen platform and workload model. Existing gateways are considered during migration so that the overlay does not introduce unintended duplicate ownership or inconsistent neighbour information.
External network access is integrated through a deliberate border design. We review route exchange, default routes and stateful service paths in both directions. The overlay should expose only the intended tenant services to the wider network. A border failure or external route change is assessed for its effect on app traffic, not just for the control-plane event it generates.
Validate forwarding and isolation together
Testing begins only after the underlay prerequisites are established. We then check expected overlay peers, endpoint information, imported routes and representative app flows. Both same-subnet and routed traffic are considered where relevant. A successful test within one tenant does not prove that all border and shared-service paths work correctly.
Negative tests confirm the intended separation, with authorisation and scope agreed in advance. We also exercise supported workload movement and chosen network failures where safe. Restoration is observed so that stale or conflicting state is not overlooked. The acceptance record distinguishes shown behaviour from scenarios that remain dependent on vendor support or future testing.
Make the overlay operable over time
The handover includes identifier schedules, route-policy intent, gateway standards and a method for tracing an app across layers. Monitoring and setup validation should identify inconsistent mappings and unexpected route imports without making unauthorised corrections. Changes to the overlay are reviewed against the underlying physical and software constraints.
MCI can deliver overlay design for a new fabric or review a current Cisco setup with policy or reachability concerns. Related work includes tenant segmentation and border leaf integration. Bring the workload needs, underlay design and current identifier scheme to the first discussion. We will define a supported overlay and the tests needed to establish its intended service boundaries.
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.
+44 203 196 6566Choose option 1
sales@proxar.co.ukUK-wide service.
Most of our engineers are based in Kent, with a focus on London, Sussex, Essex and Berkshire.
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