D-Link DSL-2877AL - Diagnostics

D-Link DSL-2877AL Dual Band Wireless AC750 VDSL/ADSL2+ Modem Router User Manual
Section 3 - Web User Interface Configuration
Page 91
Diagnostics
To access the Diagnostics page, click on the Maintenance menu link at the top, and then click on the Diagnostics menu link on the left.
The Diagnostic Test page shows the test results for the connectivity of the physical
layer and protocol layer for both LAN and WAN sides.