SRA Cheat Sheet 2026: One-Page Review of Must-Know Facts

The Nokia SRA Route at a Glance

Nokia Service Routing Architect (SRA) is a multi-exam certification, and that single fact trips up more candidates than any technical topic. It is distinct from the NRS I and NRS II credentials, and it is not one test with one question count and one duration. It is a sequence: five written exams followed by a hands-on practical lab on live 7750 SR service networks. This cheat sheet condenses the route into a one-page mental model, then walks each domain with the specific topics you should be able to explain, configure and troubleshoot.

If you are new to the credential itself, start with What Is SRA Certification? for the background, then return here for the compressed review. For a full learning plan, see the SRA Study Guide.

Eligibility and the September 8, 2026 Transition

The current route takes effect September 8, 2026 under Nokia's program update. Several details matter for anyone who started studying under the older structure:

• Separate IS-IS/OSPF, MPLS and Services Architecture exams are no longer required. Their knowledge still underpins everything in the five written exams, so they remain useful preparation, but they are not current prerequisites.
• Multicast 4A0-108 is retired. It is not a current SRA requirement, so do not spend exam-prep time on it for credential purposes.
• The lab page may display superseded prerequisites. For current eligibility, rely on the dated September 8, 2026 program update and the current certification table rather than the older lab page text.
• Previously lab-eligible candidates retain that eligibility under the announced transition.
• Course prerequisites are recommendations, not exam requirements. Training is not mandatory to attempt the examinations.

For a deeper treatment of qualification mechanics, read SRA Requirements: Eligibility, Prerequisites and How to Qualify. For budgeting, see SRA Certification Cost; note that no single overall exam fee is established for the whole route, since it spans multiple exams plus a lab.

BGP for Internet Routing (4A0-102)

What to be able to explain cold

Policy is where BGP knowledge converts to points. Be ready to read a routing policy, predict which routes are accepted, rejected or modified, and diagnose why a prefix is not being advertised. Pair that with attribute behavior: you should know how attributes influence path selection and how the IGP interacts with next-hop reachability.

For iBGP scale, be able to contrast route reflectors with confederations, including what each does to path visibility. Then connect that to advertise-external, add-paths and fast reroute, which all exist to change what a router knows about alternate paths and how quickly it can switch to them. A common weak spot is understanding why a feature is needed (hidden paths in a route-reflector design, for example) rather than just recalling its name.

Virtual Private LAN Services (4A0-105)

High-yield concepts

• SAP versus SDP: the SAP is the customer-facing attachment point; the SDP is the provider-side tunnel construct carrying pseudowires. Keep their roles straight when reading configurations.
• Distributed service MTU: MTU must be consistent across the service, and mismatches are a classic cause of services that come up but do not pass traffic as expected.
• FDB behavior: know how MAC learning populates the forwarding database and what happens as it grows.
• Loop prevention and redundancy: contrast RSTP, M-VPLS with STP, MC-LAG and active/standby pseudowires, and be able to say when each fits.
• Scale: H-VPLS reduces full-mesh pseudowire burden; PBB addresses excessive MAC learning by separating customer and backbone MAC domains.

For how each of these content areas is organized and why the groups matter, the SRA Exam Domains guide expands on all six.

Virtual Private Routed Networks (4A0-106)

The mental model that ties it together

Think of every VPRN problem as a question about route distribution and label signaling. Route distinguishers keep overlapping customer prefixes unique; route targets control which VRFs import and export which routes. Once you can reason from those two, hub-and-spoke, full-mesh and extranet designs become variations on import/export policy rather than separate topics.

Inter-AS Options A, B and C and carrier-supporting-carrier are the most conceptually dense parts of this domain. For each, practice stating three things: what routes are exchanged between the autonomous systems, what the forwarding path looks like, and what you would check first if traffic failed.

Quality of Service (4A0-107)

Distinctions the exam rewards

• Shaping versus policing: queues buffer and delay; policers meter and drop or remark. Know where each applies.
• Classification precedence: understand match precedence and what the default network policy does when nothing else matches.
• Customer-header versus encapsulation-header marking: be clear on which header a given policy action affects, and how that plays out across Layer-2, VPRN and IES services.
• Hierarchy: trace how traffic flows from a queue or policer through hierarchical schedulers to the egress port.

Because QoS is policy-construction heavy, it is one of the domains where candidates feel the gap between recognizing a concept and building it. That difficulty is discussed further in How Hard Is the SRA Exam?

Ethernet VPN Services (4A0-115)

How to hold EVPN in your head

Organize EVPN by what each route type does. IMET routes build the flooding list; MAC routes populate the FDB through the control plane rather than flooding-and-learning alone; proxy-ARP reduces broadcast. Then layer on IRB for routing between subnets, and compare the asymmetric and symmetric models by asking where the routing lookup happens and what each design requires configured on each node.

Multihoming is its own cluster: Ethernet segments, designated-forwarder election, split-horizon protection for BUM traffic, aliasing for all-active load distribution, and single-active behavior. Learn these as a set, since each exists to solve a problem created by the others.

SRA Practical Lab (ASRA4A0)

Practical scope by area

• BGP: AS peering, messages and attributes, reflectors and confederations, advertisement and redistribution, selection, policy and regular expressions, advertise-external, add-paths and FRR.
• QoS: classification, queues and buffers, policing and shaping, scheduling, rate limits and resources, hierarchical and egress scheduling, CFHP, marking, and application to Layer-2 and Layer-3 services.
• VPLS: SAP encapsulation and forwarding, MTU, FDB size and alarms, MAC aging/learning/discard, protection and OAM; BGP autodiscovery, BGP VPLS and LDP VPLS with autodiscovery; STP/M-VPLS-RSTP, MC-LAG and pseudowire resilience; ring and full-mesh, H-VPLS and PBB scale.
• VPRN: label signaling, RD/RT, VRF import/export, route selection, the various topologies, PE-CE routing with static, OSPF or BGP, and inter-AS A/B/C.

Notice that the lab scope lists BGP, QoS, VPLS and VPRN in detail. The written EVPN exam is its own gate, so give EVPN written-exam preparation its own attention rather than assuming lab practice covers it. For a view of how the practical stage affects overall difficulty, see How Hard Is the SRA Exam?, and for scoring questions see SRA Passing Score.

The 4A0-C02 Composite and Common Misreadings

The optional 4A0-C02 composite is a substitute for four written exams only: 4A0-102, 4A0-105, 4A0-106 and 4A0-107. It does not replace 4A0-115, and it does not replace the practical lab. Candidates who read "composite" and assume it shortens the whole route are mistaken.

Related reading on those unsettled numbers: SRA Pass Rate, SRA Certification Cost and SRA Exam Dates. Also be careful with timing: NRS I changes announced for March 2027 must not be applied to the SRA scope described here.

Sequencing the Domains in Your Plan

One short note on ordering, tied directly to how the domains depend on each other. BGP underpins VPRN, so it comes first. VPLS and VPRN then give you the Layer-2 and Layer-3 service models that EVPN extends. QoS is largely independent and can slot in alongside, but it benefits from having real services to apply policies to.

For broader planning, see the SRA Study Guide. To check your recall on each domain with original supplemental questions, use the SRA practice tests; they are independent study material, not issuer-endorsed, and do not reproduce actual exam questions or guarantee results.

Where the Credential Fits

The SRA targets engineers who design, build and troubleshoot service-provider networks on Nokia platforms: people working with IP/MPLS cores, Layer-2 and Layer-3 VPN services, and data-center interconnect. Roles that use these skills tend to sit in service providers, large network operators and integrators that deploy 7750 SR gear. For the market side, see SRA Jobs and the SRA Salary Guide, and for an overall value assessment, Is the SRA Certification Worth It?. This article intentionally avoids quoting earnings figures, since none are established for this review.

If you want a cleaner introduction to the terminology first, What Is SRA? covers the basics. When you are ready to test yourself, start from the main SRA Exam Prep site.

Frequently Asked Questions