Connect. Secure. Manage.
Catalyst 9800 High Availability
Design and validate high availability for Cisco Catalyst 9800 controllers, accounting for failure detection, client recovery and maintenance procedures.
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.
Catalyst 9800 high availability plans wireless service through specified controller faults. We check the supported pair, links between units and the upstream network, then agree controlled tests. The results show what the design can recover from. Controller redundancy alone is not a guarantee that every client app will survive every interruption.
Coverage and capacity
Design Wi-Fi around the spaces, devices and traffic that depend on it.
Secure access
Align authentication, segmentation and guest access with the wider network.
Measured performance
Validate roaming, interference and user experience instead of relying on signal bars.
Define what the pair must withstand
The first discussion concerns service impact. A controller failure, a lost switch uplink and a failed authentication server are different events. We map the components needed by current clients and by new clients attempting to connect. The design should identify which failures the controller pair addresses and which require separate protection elsewhere in the network.
Physical independence also matters. Two appliances may share a power source or aggregation switch; two virtual controllers may depend on one hypervisor or storage platform. We review those common dependencies with the infrastructure team. The resulting resilience statement should be specific enough for a business owner to understand what remains vulnerable, rather than presenting two controller instances as evidence that the entire wireless service is redundant.
Standards & partnerships
Confidence in the team behind your network.
Cisco Partner
Cisco Meraki
Cyber Essentials
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Check the supported pairing
High-availability support depends on the controller models, software and rollout arrangement. We check that the proposed devices can form the required supported pair and that their relevant settings are aligned. A spare controller from a different platform family should not be assumed suitable simply because it runs similar commands. Capacity and entitlement must also fit the service expected after a failure.
We inspect the current state before joining controllers. Forming a pair can change setup ownership, so both current settings and management details need protection. The rollout plan identifies which setup is authoritative and how each device will be reached during the work. This is particularly important when an established controller is being paired with a new unit rather than when two unused devices are staged together.
A useful starting point
Not sure where to start?
Bring the requirement. We will help you define the engineering work.
Design redundancy and management paths
Cisco’s supported stateful-switchover arrangements use dedicated redundancy communication and, where applicable, redundancy-management network access. These paths have different purposes from ordinary client forwarding. We document their addressing, physical or virtual interfaces and network dependencies, checking the exact platform guidance rather than copying a diagram from a different rollout.
Failure detection must remain meaningful when part of the surrounding network is unavailable. We review what each controller can observe and how gateway reachability contributes to the design. Cabling, switching and any intermediate infrastructure are included in the assessment. The aim is predictable role ownership under the agreed fault scenarios, not merely a healthy peer connection while every external component is working normally.
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 failover with the wider service
A controller switchover can preserve relevant wireless state in supported circumstances, but upstream forwarding, authentication and app sessions still need consideration. We trace representative traffic through the controller, gateway and firewall. If those systems depend on a failed common component, controller redundancy cannot restore the missing service. New client authentication may also behave differently from traffic belonging to an already connected device.
We therefore test the outcomes that matter to the customer. A voice handset, warehouse scanner and browser session may reveal different effects during the same event. We record the conditions and observed interruption rather than using an admin status message as the sole acceptance criterion. Any application-owner testing required beyond network reachability is agreed before the maintenance window.
Plan maintenance and replacement
A redundant pair still needs software maintenance, backup and lifecycle management. We review the supported upgrade procedure and its prerequisites for the particular release. Reduced-impact methods should not be presented as universally interruption-free. The change plan states the expected effect, the validation steps and any recovery limitations, including when a return to the earlier software or setup is practical.
Replacement procedures deserve equal attention. Engineers should know how to identify the failed member, prepare a replacement and avoid introducing stale setup. We capture the normal roles and redundancy state in the handover. A later hardware swap should follow a tested process, not rely on a technician remembering how the original pair was assembled months or years earlier.
Verify readiness and retain useful evidence
Acceptance includes peer state, setup alignment, management access and agreed failure tests. We check that monitoring distinguishes a lost standby from a complete service outage. Both require action, but their operational urgency and customer communication differ. Restoration is tested as carefully as failure because an unstable return can create a second interruption after the first incident appears resolved.
MCI can include this work within a Catalyst 9800 deployment or review a current pair independently. Provide the controller models, topology and the failure behaviour you need to improve. We will define the supported design, safe test scope and support duties, leaving you with evidence of the resilience actually shown and a clear record of the dependencies that remain outside it.
Technical references
- Catalyst 9800 HA SSO configuration — Cisco / Cisco Meraki
- Catalyst 9800 configuration best practices — Cisco / Cisco Meraki
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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