Troubleshooting Tip: VDSL issues on FortiGate 80F-DSL

[ezhupa]

Description	This article describes how to resolve an issue where a DSL link is not coming up when using FortiGate 80F-DSL.
Scope	FortiGate, FortiOS.
Solution	When trying to establish a VDSL connection between a 80F-DSL FortiGate with an inbuilt modem, there are sometimes issues with the DSL link not establishing. In order to troubleshoot the issue further, run the following debug commands:  diagnose debug reset diag debug console timestamp enable diagnose debug application dsl -1 diagnose debug enable To stop the debugging: diagnose debug disable diagnose debug reset Sometimes, a German ISP provider such as Deutsche Telecom is in use and the DSL negotiation fails in the early stages: 2024-07-09 06:27:16 adsl2plus_status_ecnt: retcode=success, linkStatus=down 2024-07-09 06:27:16 DSL WAN IP: 0.0.0.0 2024-07-09 06:27:16 DSL intf IP lost. Reset timeout remained=0 2024-07-09 06:27:16 adsl2plus_check_status begin reconfig.... 2024-07-09 06:27:16 adsl2plus_sync_ecnt: 2024-07-09 06:27:16 adsl2plus_check_status done reconfig. 2024-07-09 06:27:16 adsl2plus_check_status[1435]: R[1]V[0]L[0] S[0]U[0] 2024-07-09 06:27:16 adsl2plus_check_status[1437]: ADSL's link is down 2024-07-09 06:27:16 adsl2plus_check_status[1438]: Data link is down In cases like this, test with the following settings: config system interface edit <dsl> set phy-mode vdsl2 set tc-mode ptm set annex b end After performing this change, the data link should go up.