Connect. Secure. Manage.
Internet Provider Migration
Move a business network between internet providers with a plan for addressing, DNS dependencies, firewall changes and controlled cutover testing.
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.
Internet provider migration changes the connection on which users, published services and remote access may depend. The circuit itself is only part of the transition: public addressing, routing, DNS and external permissions can all be affected. MCI Network Services plans and carries out Cisco and Meraki edge changes so the new service is validated before the old one is removed, with clear ownership of the tasks that sit with the customer and each provider.
The whole path
Understand how sites, providers, cloud networks and security controls fit together.
Resilience that can be tested
Separate a second circuit from genuine end-to-end service resilience.
Provider coordination
Keep addressing, routing and escalation ownership clear across organisations.
Inventory the dependencies of the current connection
We identify outbound users, public applications, site-to-site VPNs, remote access and third-party systems that recognise the existing public addresses. The review also covers monitoring, email-related services where relevant and provider-managed equipment. A migration can appear successful for ordinary browsing while a less visible business integration remains unavailable.
The current service record includes addressing, handoff configuration, routing and contractual responsibilities. We establish which equipment belongs to the provider and which settings can be changed by the customer's engineers. This avoids discovering during the cutover that an essential configuration requires a separate carrier request or an unavailable administrative account.
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
Validate the new handoff before scheduling cutover
The new provider's service should be checked against the agreed specification. We review physical presentation, addressing, routing, usable bandwidth and any restrictions that affect the proposed edge design. An installation-complete message is not the same as an end-to-end test from the customer's network.
Where practical, the new circuit is tested independently while the old service remains active. We confirm the required destinations and provider support contacts, including the procedure for reporting a fault during the migration window. The implementation plan should not rely on an untested circuit arriving ready at the exact moment the old one is disconnected.
A useful starting point
Not sure where to start?
Bring the requirement. We will help you define the engineering work.
Plan public addressing and external permissions
A provider change may require new public addresses. We identify the affected translations, published records, VPN endpoints and external allowlists. Address portability is checked against the actual allocation and routing arrangements rather than assumed from the customer's continued use of the same equipment.
External organisations may need time to update their controls. We prepare a dependency register with owners, requested changes and confirmation status. For critical counterparties, the cutover plan includes a coordinated test so that a missing remote permission is not mistaken for a local firewall or routing fault.
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 ↗Coordinate DNS, certificates and application endpoints
Public DNS changes should be planned with the relevant service owners and the expected caching behaviour. Lowering a record's lifetime shortly before cutover does not erase copies already cached elsewhere. We allow for the transition and avoid promising that every external user will move to the new address simultaneously.
Certificates and application configuration are reviewed where names or endpoints change. A move that preserves the hostname may still affect address-based controls, while a hostname change introduces separate trust and application dependencies. The migration plan identifies these differences rather than treating DNS as the only service-discovery mechanism in use.
Prepare the Cisco or Meraki edge changes
The configuration scope includes interfaces, default routes or BGP policy, address translation and security rules relevant to the new service. We capture the current state and review the proposed differences before deployment. Changes are introduced in a sequence that makes it possible to verify the new path without losing management access unnecessarily.
A dual-service period can reduce risk, but it requires clear path preferences. We check how existing sessions, inbound services and return traffic behave while both providers are present. Temporary routes and policies receive removal criteria so the final configuration does not retain unexplained migration exceptions.
Test the cutover against business workflows
Acceptance includes representative outbound applications, published services, VPNs and external integrations identified during discovery. Tests are performed from appropriate locations, including outside the organisation where inbound access matters. A successful speed test does not establish that all business dependencies have moved.
Rollback conditions are agreed in advance. We identify the last safe point for returning to the old service and the settings that must be restored, including external changes that may not reverse immediately. The customer knows who makes the decision and which teams must remain available until the critical checks are complete.
Retire the old service deliberately
After the agreed observation period, obsolete routes, translations, records and provider access are reviewed for removal. Circuit cancellation follows the customer's commercial process and should not precede technical acceptance merely because a target date was convenient. Retaining a temporary overlap is a decision with a cost and an owner, not an indefinite default.
MCI can manage the engineering scope of a provider change within a wider internet edge network project. Share the current and proposed services, public applications and cutover constraints. We can build a migration plan that accounts for the full dependency chain rather than treating a new cable as the completion of the move.
Technical references
- Cisco IOS XE software hardening guide — Cisco / Cisco Meraki
- ExpressRoute routing requirements — Microsoft
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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