Five SASE deployment mistakes that cause rollbacks
After watching dozens of SASE deployments, these are the five mistakes that consistently cause projects to stall, roll back, or lose executive sponsorship.
SASE deployments fail for predictable reasons. Not because the technology doesn't work — it does — but because the rollout skips steps that seem optional until they cause an outage. Here are the five mistakes I see most often.
1. Skipping the TLS bypass list
This is the number one cause of day-one rollbacks. You enable TLS decryption on the SWG without a bypass list, and suddenly banking apps break, Teams calls drop, and the EDR agent can't phone home. Certificate-pinned applications MUST bypass TLS inspection — there's no workaround.
Build your bypass list before you enable decryption. Test it with a pilot group. Add to it aggressively in the first two weeks. Our deployment cheatsheet PDF includes a starter list of 30+ domains to whitelist on day one.
2. Going straight to enforce mode
Every SWG and DLP engine has a monitor-only mode. Use it. Run in monitor-only for at least two weeks to see what your policies would block before they actually block it. The false positive rate in the first week is always higher than you expect. If you start in enforce mode, users hit broken sites, file tickets, and the project loses credibility before it delivers value.
3. Not uninstalling the legacy VPN before deploying ZTNA
The SASE agent and legacy VPN clients fight over routing tables, DNS, and proxy settings. Running both simultaneously causes intermittent connectivity issues that are nearly impossible to debug. The fix is simple: uninstall the VPN client before deploying the SASE agent. If you need VPN as a fallback, use a separate device or a browser-based VPN that doesn't install a system-level driver.
4. No executive sponsor
SASE touches networking, security, identity, and endpoints — four different teams with four different budgets and four different change management processes. Without an executive sponsor who can break tie votes and prioritize resources, the project stalls at the first cross-team disagreement. The most common stall point: the networking team owns the WAN, the security team owns the proxy, and neither wants to give up control to a unified platform.
5. Measuring success too late
Capture baseline metrics BEFORE you deploy. VPN connection times, helpdesk ticket volume, malware incidents per month, MPLS costs. If you don't measure before, you can't prove improvement after. The first quarterly review with leadership should show concrete numbers: "We blocked 4,200 malicious domains, reduced VPN connection time from 12 seconds to under 1 second, and eliminated 60% of remote access helpdesk tickets." Without baselines, you're guessing.
The common thread
All five mistakes share a root cause: rushing to deploy the technology before the organization is ready. SASE is a phased project — DNS first, SWG second, ZTNA third, CASB/DLP fourth, SD-WAN last. Each phase has prerequisites. Skip them and you'll spend more time rolling back than rolling out.