Zscaler — Architecture Overview
Summary
Zscaler provides cloud-delivered internet security (ZIA) and secure private application access (ZPA) without a traditional site-to-site or client VPN. Traffic is routed through Zscaler's cloud regardless of whether a user is on-premises or remote, enforcing consistent policy everywhere.
Architecture Diagram
flowchart LR
user[User Device] --> zcc[Zscaler Client<br/>Connector]
zcc --> zia[Zscaler Internet<br/>Access - ZIA]
zcc --> zpa[Zscaler Private<br/>Access - ZPA]
zia --> internet[Public Internet]
zpa --> connector[App Connector]
connector --> internal[Internal Apps<br/>on-prem / cloud]
zcc <--> okta[Okta SSO]
Components
| Component | Role |
|---|---|
| Zscaler Client Connector | Lightweight agent on endpoint, routes traffic to the Zscaler cloud |
| ZIA (Internet Access) | Inspects and filters general internet-bound traffic |
| ZPA (Private Access) | Brokers zero-trust access to internal apps without exposing the network |
| App Connector | Lightweight connector deployed near internal apps, establishes outbound-only tunnel to ZPA |
| Okta | Identity provider for authentication before access is granted |
Traffic Flow
- User's device runs Client Connector, which authenticates via Okta SSO.
- General web traffic routes through ZIA for inspection and policy enforcement.
- Requests for internal apps route through ZPA instead.
- ZPA matches the request to an App Connector near the target app — no inbound firewall ports are opened.
- Access is granted per-app, per-policy — not network-wide, unlike a traditional VPN.