thinQmaster Virtual testing partner Adaptive practice exams that find your weak spots and drill them. Every answer explained. From $69
Enroll

thinQmaster

Find your exam

Five questions free, before you decide.

Step 1 · choose a vendor

In one of our camps? Your practice exams come with the tuition — they are on your study page already.

Routing & Switching · Intermediate

STP Timers

The 802.1D timers: hello time 2 s, forward delay 15 s and max age 20 s, all dictated by the root bridge.

Definition

Hello time sets BPDU frequency, forward delay governs listening and learning durations, and max age defines how long stored BPDU information is kept. They should only be tuned on the root, and changes affect convergence and stability.

Example

spanning-tree vlan 10 hello-time 1

Exam tip

Timers configured on non-root switches have no effect; the root's values are used.

Related terms