Many SSL-VPN connections disconnected in one minute
Our company using ssl-vpn with two Fortigate (v6.4.0 build1579 (GA)) VMs running on Azure.
A total of about 1,500 users are usually connected them from home and have been in operation for about a year and a half.
But 2 weeks ago, around 12:23 p.m. most SSL-VPN sessions were suddenly disconnected in one minute.
Fortigate did not reboot and not out of memory situation during that time, and there was no system error output to syslog.
(We restart Fortigate every midnight for stable operation.)
We thought Azure environment might suspiciously, but MS support said that there was no failure in that time zone.
Have anyone experienced similar symptoms?
syslog shows many ssl-vpn disconnect messages like below,
2021/09/23 12:23:50 info sslvpn FortiSslvpn: 3100: Ras: connection to fortissl terminated
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