Azure Basics · Module 05

Network Traffic – Routing, Private Link, Load Balancer, Application Gateway

Steer traffic with route tables, reach PaaS services privately with service endpoints and Private Link, and distribute load at L4 with Load Balancer and at L7 with Application Gateway.

Practice interactively →

What you will learn

• Read system routes, create UDRs through an NVA and attach them to subnets
• Compare service endpoints with private endpoints
• Choose public/internal Load Balancer with the Standard SKU
• Configure backend pools, rules, health probes and session persistence
• Know when to use Application Gateway instead of Load Balancer

Lessons

1. System Routes and User-Defined Routes

   Azure creates system routes for subnets, VNets, the Internet and gateways; a route table holds UDRs that override the next hop (through a firewall/NVA, say) and is attached to subnets.

2. Service Endpoints and Private Link

   A service endpoint lets a subnet reach PaaS services over the backbone and lets the service lock itself to that subnet, but still uses the public endpoint; a private endpoint gives one resource a private IP in your VNet.

3. Azure Load Balancer — Types and SKUs

   Load Balancer is an L4 (TCP/UDP) balancer; a public LB takes Internet traffic, an internal LB works only inside the VNet; only the Standard SKU is used now (closed by default, zone support, SLA).

4. Backend Pools, Rules, Health Probes and Session Persistence

   A rule maps frontend IP:port to backend pool:port; a health probe takes failed VMs out of rotation; session persistence keeps a client on the same VM by IP or IP + protocol.

5. Application Gateway

   Application Gateway is an L7 load balancer for the web — it routes by URL path or host name with listeners, rules, backend pools, health probes, TLS termination and an optional WAF.