Troubleshooting Tip: SSL VPN stops working for remote and local users due to the FNBAMD process

Description

This article describes behavior where FortiGate stops accepting new SSL VPN connections due to the FNBAMD process.

Scope

FortiGate versions before 7.4.12.

Solution

Users configure an standard SSL VPN connection for local and remote users.

Check the crashlog and validate whether there are multiple fnbamd crashes.

diagnose debug crashlog read | grep 2026

111: 2026-03-14 15:48:14 <03214> firmware FortiGate-100 v7.4.11,build2878b2878,260126 (GA.M) (Release)

112: 2026-03-14 15:48:14 <03214> application fnbamd

Capture some debug outputs from the VPN and validate the fnbamd process remains stuck.

diagnose debug disable

diagnose debug reset

diagnose vpn ssl debug-filter src-addr4 x.x.x.x → replace x.x.x.x with the public IP of the user 

diagnose debug application sslvpn -1

diagnose debug application fnbamd -1

diagnose debug enable

FGT_Test# [15553:root:2]allocSSLConn:303 sconn 0x7f9c2a558000 (0:root)

[15553:root:2]SSL state:before SSL initialization (180.32.13.42)

[15556:root:2]rmt_web_auth_info_parser_common:534 no session id in auth info

[15556:root:2]rmt_web_access_check:805 access failed, uri=[/remote/logincheck],ret=5003,

[15556:root:2]fsv_logincheck_common_handler:1489 user 'TEST_USER' has a matched local entry.

[15556:root:2]sslvpn_validate_user_group_list:2969 got user (1:0), group (20:0) peer group (0).

[15556:root:2]sslvpn_update_user_group_list:1851 got user (1:0), group (20:0), peer group (0) after update.

[15556:root:2]sslvpn_authenticate_user:203 authenticate user: [TEST_USER]

[15556:root:2]sslvpn_authenticate_user:221 create fam state

[15556:root:2][fam_auth_send_req_internal:445] FNBAM opt = 0X201420

[15556:root:2]fam_auth_send_req_internal:514 fnbam_auth return: 4\

Restart the process with the following commands:

FGT_M # diagnose system process pidof fnbamd

10498

FGT_M # diagnose system kill 11 10498

Test the SSL VPN connection now works.