Search the practice set
126 questions, 454 terms and 400 topics in 20 areas.
33 results for “Network Troubleshooting”
Content Delivery Network
A geographically distributed cache that serves content from a location near the user instead of from the origin.
Anycast
Advertising the same IP address from many locations, so the network routes each client to the topologically nearest one.
Availability Zone
One or more physically separate data centres inside a cloud region, with independent power, cooling and network, connected by low-latency links.
CAP Theorem
During a network partition a distributed system must choose between consistency and availability; it cannot have both.
Egress Filtering
Restricting which destinations a workload may connect to outbound — the control that limits data exfiltration and SSRF impact, and the one most often omitted.
Egress Path Analysis
Tracing where data physically moves in an architecture, because transfer charges follow paths that appear nowhere on the diagram.
Encryption at Rest and in Transit
Protecting stored data from disclosure if the medium is obtained, and network data from disclosure if the path is observed — two different controls against two different threats.
Global Traffic Management
The layer that decides which region a given user reaches, using DNS, anycast or an edge network, and that performs regional failover.
Microsegmentation
Enforcing fine-grained network policy between individual workloads rather than between broad network zones, so a compromise cannot move laterally.
Monzo's Microservice Estate
Monzo runs a bank on well over a thousand microservices, and the interesting engineering is in the platform and network isolation that makes that number survivable.
NAT Gateway
A managed device that lets instances in a private subnet make outbound connections without being reachable inbound.
Partition Tolerance
The ability to keep operating when the network drops or delays messages between nodes — not a choice, but a property of any system spanning more than one machine.
Pod
The smallest deployable unit in Kubernetes — one or more containers that share a network namespace, storage volumes and a lifecycle, scheduled together on one node.
Security Group
A stateful, instance-level firewall that allows specified traffic and denies everything else by default.
Service Discovery
The mechanism by which a caller finds a currently healthy network address for a service whose instances are ephemeral.
Subnet
A subdivision of a network's address range, used as the unit of routing and, in cloud, of availability-zone placement.
TLS
The protocol that gives a network connection encryption, integrity and server authentication, underneath HTTPS and most other secure transports.
Virtual Private Cloud
A logically isolated network inside a cloud provider, with an address range you control and explicit rules for what may enter and leave.
Web Application Firewall
A filter in front of an application that inspects HTTP requests and blocks those matching known attack patterns — useful as a layer, dangerous as a substitute.
Zero Trust
A security model that grants no implicit trust from network position, and authenticates and authorises every request individually.
A 43-second network partition caused GitHub over 24 hours of degraded service in 2018. How does a 43-second event become a day-long incident?
The case, as publicly reported On 21 October 2018, routine maintenance replacing failing optical equipment caused a 43 second loss of connectivity between GitHu
A card payment authorisation service runs active-active across two regions. A network partition splits them. Do you keep accepting authorisations, and what breaks either way?
What the interviewer is testing Whether you can apply CAP to a domain where the cost of each choice is concrete, and whether you recognise that "it depends" has
Design the network layout for a three-tier application in one cloud region. What are the decisions you cannot easily change later?
What the interviewer is testing Whether you know which network decisions are cheap and which are effectively permanent. This is a knowledge question with a clea
In July 2019 a single regex deployed globally took Cloudflare's network to 100% CPU within seconds. What does this say about how configuration should be released?
The case, as publicly reported On 2 July 2019, Cloudflare deployed a new managed WAF rule. It contained a regular expression that caused catastrophic backtracki
Network Troubleshooting
Flow logs, packet paths, and localising a problem to a hop.
Network & Egress Costs
Cross-zone and cross-region transfer that appears on no diagram.
Network Performance
Latency floors, bandwidth-delay product, and what no code change fixes.
Network Performance Tuning
Keep-alive, compression, payload size and round-trip elimination.
Network Security
Segmentation, egress control and limiting lateral movement.
Landing Zones
A governed foundation of accounts, network, identity and guardrails.
Modular Monolith
Enforced internal boundaries without a network between them.
Networking
General material on the network path underneath an architecture.
Zero Trust
No implicit trust from network position; authorise every request.