How a lesson's access starts, runs and ends.
DNS Angel has three parts: the DNS Agent on each school Windows computer, the DNS Angel app for teachers and school administrators, and IronSights, who set it up and watch it.
Three parts, one job
The DNS Agent
Runs on every school Windows computer and in Chrome, Edge and Firefox. It applies the school's filter all day, in every room, and on school laptops away from school.
The DNS Angel app
Teachers allow sites for a lesson. School administrators see live access, rooms, computers and Activity, and hold the Stop all access switch.
IronSights
Sets up sign-in, classes, rooms and your normal filter, then checks every 15 minutes that each school's rules are as they should be.
The life of one allow
Every allow goes through the same steps, and the teacher sees each one named in words.
Measured, not promised
In our lab on 3 October 2026, access reached a computer in 286 to 322 seconds and was removed 288 to 290 seconds after its end time, over five runs. So we say "usually within 5 minutes", never "instant".
Allow 0 min
The teacher picks the site, 30, 45 or 60 minutes, and the room or class. DNS Angel checks it against Always blocked, Never allow and Teacher limits.
Starting Usually within 5 min
Access reaches the computers in that room or class. The teacher sees Starting until it's live.
Live until 11:45 The lesson
The teacher sees a countdown. School administrators see it in Live access. The teacher or a school administrator can end it early.
Ending About 5 min
At the end time, DNS Angel ends access by itself, and the normal filter is back within about 5 minutes.
On the record Afterwards
Who allowed what, where, for how long, and how it ended goes into the school's Activity.
Five ways schools handle a blocked lesson site
Most schools use one or more of these today. The table compares them on the four things a school needs.
| Approach | Works during the lesson | Ends by itself | Stays inside your limits | Leaders can see each one |
|---|---|---|---|---|
| Ask IT and waitSafe, but the ticket usually lands after the lesson, and someone has to remember to undo it. | No | Partly | Yes | Partly |
| Unblock it for everyoneQuick, then it stays open for months and nobody remembers why. | Yes | No | No | No |
| Give teachers the filter consoleFast, but every teacher now holds the master key. | Yes | No | No | Partly |
| Unblock for the class session, or a bypass codeCommon in classroom tools and it does end, but a code can open any site that isn't locked, and what was opened isn't always easy for leaders to see. | Yes | Yes | Partly | Partly |
| Timed access with a record (DNS Angel)One site or lesson set, one room or class, a fixed time, inside limits you set, and every allow on the record. | Yes | Yes | Yes | Yes |
Questions about how it works
Something else? Ask us directly.
What does DNS filtering do?
DNS filtering checks each website a computer tries to reach against a set of rules before it loads. If the site is in a blocked category or on a block list, the computer can't reach it. DNS Angel's DNS Agent also filters inside Chrome, Edge and Firefox, so rules can apply to pages as well as whole sites.
Why does access take about 5 minutes to start?
The DNS Agent on each computer checks for new rules every few minutes. In our lab on 3 October 2026, access reached a computer in 286 to 322 seconds. Teachers see Starting until it's live, and lesson sets make it quick to allow everything as the class arrives.
What if access doesn't end on time?
DNS Angel ends access by itself at the end time and checks the result. If access is still on, the teacher and your school administrators see Couldn't end yet, and IronSights is alerted. It's recorded either way.
Can a teacher schedule access for later in the day?
Not yet. For now, access starts when the teacher presses Allow. Lesson sets keep it to a few seconds of effort as the class walks in.
Can a teacher allow one YouTube video rather than all of YouTube?
No. Allowing YouTube allows the site for that room or class for the lesson, then it ends. Your school can keep YouTube on its Never allow list if it prefers.
See how it would work at your school.
A walkthrough with the IronSights team: how teachers allow a site, what your IT team controls, what leaders can see, and how we set it up for you.