Cisco & Meraki specialists. Across the UK.
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Cisco ISE Certificate Authentication

Design EAP-TLS authentication with Cisco ISE, covering certificate trust, device enrolment, expiry handling and failed-authentication diagnosis.

Cisco Partner since 2009 Projects & ongoing support

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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 ISE certificate authentication uses a digital credential as part of network sign-in. We plan supported EAP-TLS access with the identity and endpoint teams. The work covers trust, issue, renewal and the response to a lost device. A sound certificate process and the right endpoint settings are both needed for the access rules to work.

01

Defined trust

Make access boundaries explicit rather than relying on an assumed internal network.

02

Controlled access

Connect identity, policy and network enforcement to the services people actually use.

03

Evidence for change

Test the intended security outcome and retain useful operational records.

Decide what the certificate represents

A machine certificate and a user certificate answer different questions. The first may establish that a managed device holds an approved credential. The second may identify a person using it. We agree the required identity at each stage, including pre-login access and situations where several people share one workstation.

That decision shapes the certificate profile and ISE policy. We check which certificate attributes will be used and whether an extra directory lookup is required for authorisation. A trusted issuer should not imply that every certificate from that issuer receives the same network access. The intended mapping must be narrow enough to distinguish the population actually authorised for the service.

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01Network infrastructure designed around the workloads it carries.
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Cisco MerakiCisco Meraki
ISO 9001Quality management
ISO 27001Information security
Cyber EssentialsCyber Essentials
Cyber Essentials PlusCyber Essentials Plus

MCI Network Services is operated by Proxar Ltd. Certifications apply to the certified legal entity and the scope of its certificates. View accreditation information

Establish both sides of trust

The endpoint must check the authentication server, and ISE must check the presented client credential according to the chosen design. We review the relevant certificate chains, identities, validity periods and supported cryptographic settings. A missing intermediate certificate or an unexpected server name can prevent access even when the issuing authority itself is trusted.

We avoid asking users to resolve trust warnings by accepting whatever appears. Managed profiles should identify the intended service and distribute the necessary trust material through the customer's approved endpoint process. The project includes a check that a client refuses an inappropriate authentication server, not merely that it accepts the legitimate one.

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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.

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Make enrolment part of the service

A certificate-based network needs a way to provision a device before it has ordinary network access. We map the enrolment route, required management network access and the team authorised to issue or approve certificates. New starters, replacement laptops and rebuilt devices are included in that process.

Private keys must remain protected under the endpoint design. We discuss exportability, device storage and admin access with the relevant owner rather than treating a certificate file as a harmless setup attachment. The proposal distinguishes work on ISE from work on the certificate authority and endpoint-management system. So that duties do not fall between teams.

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03Enterprise switching and routing, built to be operated.

Design renewal before the first expiry

Renewal is a routine operating need, not an exceptional incident. We agree who monitors validity, how replacement credentials reach devices and how long old and new trust chains may overlap during a planned change. A device that has been offline for months needs a recovery path that does not depend on an already expired network credential.

Changes to an issuing authority or authentication-server certificate can affect an entire estate. We prepare a staged transition and test representative clients before removing old trust. A successful certificate import into ISE does not prove that all endpoints recognise the new chain or that the intended certificate has been chosen for each service.

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04Resilient infrastructure from rack to service path.

Define revocation and exception behaviour

The organisation needs an answer for a lost device, departing user or compromised credential. We review revocation mechanisms supported by the chosen release and the availability of the services used to check status. The agreed behaviour when those services are unavailable is a security and availability decision that must be recorded.

Revoking a credential and terminating an established network session are related but distinct actions. We test the intended response, including reauthentication and any supported session-change mechanism. The report explains what takes effect immediately and what depends on a later event, rather than implying that a certificate change instantaneously removes every current connection.

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05Data-centre connectivity with clear physical and logical boundaries.

Test identity and permission together

The pilot includes valid, expired, untrusted and incorrectly identified credentials, and a device in the wrong authorisation group. We compare the ISE decision with the actual network access. A certificate may authenticate successfully while the later group mapping or enforcement result is incorrect.

We also test common operating events: reboot, sleep, user change and renewal. Evidence is recorded without exposing private keys or unnecessary personal data. Where a particular operating system or client version cannot support the intended workflow, the limitation is documented and a separate approach is agreed rather than concealed behind a permissive fallback.

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06Visibility, monitoring and operational control.

Keep certificate access maintainable

MCI delivers the trust model, policy mapping, renewal duties and a practical fault-isolation procedure. This work can form part of Cisco ISE deployment or a focused conversion of a current password-based service. The aim is a network credential that is difficult to misuse and straightforward to operate, with ownership that continues after the initial certificate rollout.

Illustrative Cisco and Meraki data-centre network infrastructure
07Network infrastructure designed around the workloads it carries.

Technical references

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08Fibre, switching and the physical path behind the service.

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 6566

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sales@proxar.co.uk

UK-wide service.
Most of our engineers are based in Kent, with a focus on London, Sussex, Essex and Berkshire.

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