Connect. Secure. Manage.
Cisco ACI Migration
Plan migration into Cisco ACI with application dependency checks, coexistence arrangements and controlled workload-by-workload cutover.
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 ACI migration moves application connectivity and policy into a different operating model. It requires more than reproducing VLAN names on new switches. MCI Network Services plans migrations around application dependencies, gateway ownership and the coexistence of old and new networks. We help customers introduce ACI in manageable stages, with clear acceptance tests and an honest account of when rollback remains practical.
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.
Understand what must move together
We inventory workloads, addresses, gateways, security paths and shared services. Application owners help identify dependencies that may not be visible from switch configuration alone. Authentication, backup, monitoring and external partner access can all affect the order of migration. The scope distinguishes network tasks from server, storage and application changes owned by other teams.
Existing traffic observations support discovery but do not automatically define the target security policy. Some legacy communication may be obsolete or unintended. We record what is required, what is uncertain and what needs further validation. This prevents the migration from preserving every historical exception merely because removing it during the cutover would be inconvenient.
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
Agree the target policy and attachment model
The ACI design defines tenants, routing contexts, bridge domains, endpoint groups and contracts with consistent ownership. We map workloads to that model and identify where the initial transition differs from the eventual target. A staged approach may be necessary, but temporary broad access should have explicit approval and a plan for refinement.
Physical and virtual attachment requirements are checked against supported platform combinations. Server uplinks, virtual switches, VLAN allocation and MTU must align with the fabric design. We coordinate these details before workloads move so that an application fault during cutover is not caused by an unresolved disagreement between the network and platform teams.
A useful starting point
Not sure where to start?
Bring the requirement. We will help you define the engineering work.
Design coexistence without creating hidden loops
Old and new environments may need to exchange traffic while workloads are moved in waves. We define the allowed Layer 2 extensions, routing boundaries and gateway locations for each stage. Extending a network can be useful during transition but also enlarges the failure domain. The design states why the extension is needed and when it will be removed.
Route exchange and firewall paths receive particular attention. A gateway move can alter return traffic, stateful inspection and address translation even when application addresses remain unchanged. We document preferred paths and prevent unintended redistribution or transit. Each migration wave has a known operating state, not a collection of temporary connections that engineers must rediscover during an incident.
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 ↗Pilot a representative workload group
The pilot should exercise important dependencies, not just the least critical server. We select a bounded application group and agree tests with its owners. Validation includes required access, denied paths, management and supporting services. Fabric health and endpoint learning are checked alongside the application’s own observations.
The pilot also tests the operating workflow: how changes are approved, how evidence is collected and how rollback is triggered. Findings are incorporated into later waves. A successful first move does not justify removing checks from the rest of the programme, especially where later workloads use different security, virtualisation or external-connectivity arrangements.
Execute waves with clear stop conditions
Each cutover plan lists prerequisites, exact responsibilities, verification steps and the decision point for rollback. We preserve pre-change records and ensure the team has alternative management access. Changes are introduced in an order that allows problems to be isolated before the next dependency is moved. The customer knows who can authorise continuation or stop the wave.
Rollback is assessed realistically. Once application data, addressing or platform state changes, reversing network configuration alone may not restore the former service. We agree the recovery path with the relevant owners and identify any point beyond which a forward fix or wider restoration is required. That distinction belongs in the plan before the maintenance window, not after an unsuccessful test.
Complete the migration and remove temporary dependencies
Completion includes more than moving the final workload. We remove obsolete routes, temporary extensions and unused policy where authorised, update monitoring and confirm that operational documentation matches the delivered state. Retired equipment and credentials are handled through an agreed decommissioning process. The old environment is not left as an undocumented fallback that no longer has reliable support.
MCI can lead a migration programme or provide specialist design and cutover assistance alongside an internal team. Our Cisco ACI services also cover policy review and troubleshooting after transition. For an initial scope, provide the current topology, application groups and intended project constraints. We will build a migration approach that makes dependencies, risks and acceptance evidence visible at every stage.
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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