Cannot Achieve Line Sync When Replacing ADSL Router
If you have an ADSL service and a router/modem which works, and you install a new router/modem, you may be unable to achieve line sync on the new device.
When you attach the older modem, line sync is achieved.
This may occur if the DSLAM in the exchange is remembering the MAC address of the old router. Any connection attempts from a new device will be ignored.
To resolve, unplug the old device and do not attach the new device for 15 minutes. If the new device still cannot achieve line sync, leave both devices unattached for a few hours.