The ELSM hello timer is the only user-configurable timer and specifies the time in seconds between consecutive hello messages. The default value is 1 second, and the range is 1 to 128 seconds. Although other timers rely on the hold timer for their values, you do not explicitly configure the down, up, or HelloRx timers. If you modify the hello timer on one port, we recommend that you use the same hello timer value on its peer port.
A high hello timer value can increase the time it takes for the ELSM-enabled port to enter the Up state. The down timer is (2 + hold threshold) * hello timer. Assuming the default value of 2 for the hold threshold, configuring a hello timer of 128 seconds creates a down timer of (2 + 2) 128, or 512 seconds. In this scenario it would take 512 seconds for the port to transition from the Down to the Up state.