FortiGate
FortiGate Next Generation Firewall utilizes purpose-built security processors and threat intelligence security services from FortiGuard labs to deliver top-rated protection and high performance, including encrypted traffic.
asharopov
Staff
Staff
Article Id 189444

Description

 

This article describes how to check why SSL VPN connections are not possible.
This, when triggered, leaves the following traces in the crashlog:

 

diagnose debug crashlog read

 

Output example: 

 

2010-11-02 20:09:22 SSL VPN enter conserve mode.

 

The typical behavior: No SSL VPN Web portal connections are accepted. Users get the '503 Service Temporarily Unavailable' error.

 

Scope

 

FortiGate.

Solution

 

SSL VPN in FortiOS has its own Conserve Mode, which is triggered before the regular system conserve mode. This is caused by MEM tension on the system.

Troubleshooting steps:

 

  1. Check the general MEM consumption. If it is in the higher end, follow these steps:

 

Run the following command: 

 

diag sys top-summary

 

As of version 7.2.x and above, the following command can be used:

 

diag sys top-mem

 

If the Firewall is in VDOM mode, make sure to change to the VDOM.

  1. Check if SSLVPN conserve mode has occurred in the system:

 

Fortigate # diag vpn ssl statistics
SSLVPN statistics (root):
------------------
Memory unit:               1
System total memory:       2111090688
System free memory:        1140170752
SSLVPN memory margin:      314572800
SSLVPN state:              conserve

Max number of users:       1
Max number of tunnels:     0
Max number of connections: 6

Current number of users:       0
Current number of tunnels:     0
Current number of connections: 0

Solution: Adjust metrics like (UTM profiles, Traffic shaping, Logging or any process that is using large amounts of memory etc.) to reduce the MEM and Memory consumption of the FortiGate firewall. 

 

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