Networking
General material on the network path underneath an architecture.
4 to work through
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intermediate
A user in Mumbai types your URL and presses enter. Walk me through every hop until the HTML reaches their browser. Where would you look first if the page were slow?
2 min answer -
intermediate
Design the network layout for a three-tier application in one cloud region. What are the decisions you cannot easily change later?
2 min answer -
advanced
A mobility platform operates across several Southeast Asian markets where mobile networks vary enormously in quality, latency and reliability. Which network-layer decisions matter most, and which common assumption breaks first?
2 min answer -
advanced
In the October 2021 Meta outage, engineers reportedly struggled to physically access equipment because the access-control systems were also down. What class of dependency is that, and how do you find yours?
2 min answer
14 terms in this topic
Anycast
Advertising the same IP address from many locations, so the network routes each client to the topologically nearest one.
toolContent Delivery Network
A geographically distributed cache that serves content from a location near the user instead of from the origin.
protocolDNS
The distributed directory that resolves names to addresses, and a surprisingly load-bearing part of most architectures.
protocolHappy Eyeballs
Starting a second connection attempt on the other address family a few hundred milliseconds after the first, so a broken IPv6 or IPv4 path costs the …
conceptLayer 4 vs Layer 7 Load Balancing
Balancing on connection metadata (IP and port) versus on the content of the request (path, host, headers).
toolNAT Gateway
A managed device that lets instances in a private subnet make outbound connections without being reachable inbound.
case-studyNetflix Open Connect
Netflix built its own CDN and placed appliances inside ISP networks, turning the most expensive part of its cost structure into hardware it controls.
patternReverse Proxy
A server that receives client requests on behalf of one or more backends, forwarding them and returning the response.
toolSecurity Group
A stateful, instance-level firewall that allows specified traffic and denies everything else by default.
conceptSubnet
A subdivision of a network's address range, used as the unit of routing and, in cloud, of availability-zone placement.
protocolTCP/IP
The layered protocol suite underneath essentially all application traffic — IP routes packets, TCP turns them into a reliable ordered stream.
protocolTLS
The protocol that gives a network connection encryption, integrity and server authentication, underneath HTTPS and most other secure transports.
conceptVirtual 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.
protocolWebSocket
A protocol that upgrades an HTTP connection into a persistent, full-duplex channel so the server can push to the client without polling.
Neighbouring topics
TCP/IP
Handshakes, congestion control, head-of-line blocking and connection reuse.
HTTP/1.1, HTTP/2 & HTTP/3
Multiplexing, prioritisation and the transport each is built on.
DNS
Resolution, TTL behaviour, traffic steering and failover latency.
TLS & Certificates
Encryption, integrity, authentication, termination points and expiry.
Layer 4 vs Layer 7
Connection-level versus request-level balancing, and what each unlocks.
Reverse Proxies
One place for TLS, routing, caching, compression and rate limiting.
Content Delivery Networks
Edge caching, origin offload, spike absorption and dynamic content.
Firewalls & Security Groups
Default-deny, stateful rules, and restricting egress as well as ingress.
NAT & Egress
Outbound-only connectivity, its per-gigabyte cost and its zone binding.
VPC Design
Address planning, peering and the ranges you can never resize.
Subnetting
Tiering, zone binding, and sizing for an address-hungry platform.
Routing & BGP
How traffic finds you, anycast, and route withdrawal as a failure mode.
Service Mesh Networking
Sidecar proxies supplying mTLS, retries and traffic policy.
WebSockets & Realtime
Persistent bidirectional connections and the capacity model they impose.
gRPC Transport
HTTP/2 multiplexing, binary encoding and streaming semantics.
API Gateways
The single entry point, and the business logic that must stay out of it.
Network Performance
Latency floors, bandwidth-delay product, and what no code change fixes.
Private Connectivity
Private endpoints, peering and dedicated links to managed services.
Network Troubleshooting
Flow logs, packet paths, and localising a problem to a hop.