Technical Tip: Temporarily disable an IPSec VPN tunnel

[rishab444]

Description	This article describes that for troubleshooting and some configuration change scenarios, it is maybe necessary to temporarily prevent an IPSEC tunnel from attempting to initiate or respond to IKE requests.
Scope	FortiGate.
Solution	This can be achieved by disabling the tunnel interface from under Network>Interface -> Expanding the Outgoing Interface of IPSec tunnel -> 'Right-Click' the tunnel Interface -> Set Status -> Disable. From CLI: config system interface    edit <IPSec_interface_name>        set status disable     next end This will function similarly to disabling a physical interface but will simply prevent IKE from making attempts to establish a tunnel (for a site-to-site tunnel) or responding to connection attempts for this specific tunnel. To confirm the behavior, use ike debugs: dia debug application ike -1 dia debug en To stop the debug, run the following commands:    diagnose debug disable    diagnose debug reset ike 0:dc3556fc83a979ba/0000000000000000:10: responder: main mode get 1st message... ike 0:dc3556fc83a979ba/0000000000000000:10: VID RFC 3947 4A131C81070358455C5728F20E95452F ike 0:dc3556fc83a979ba/0000000000000000:10: VID draft-ietf-ipsec-nat-t-ike-03 7D9419A65310CA6F2C179D9215529D56 ike 0:dc3556fc83a979ba/0000000000000000:10: VID draft-ietf-ipsec-nat-t-ike-02 CD60464335DF21F87CFDB2FC68B6A448 ike 0:dc3556fc83a979ba/0000000000000000:10: VID draft-ietf-ipsec-nat-t-ike-02\n 90CB80913EBB696E086381B5EC427B1F ike 0:dc3556fc83a979ba/0000000000000000:10: VID draft-ietf-ipsec-nat-t-ike-01 16F6CA16E4A4066D83821A0F0AEAA862 ike 0:dc3556fc83a979ba/0000000000000000:10: VID draft-ietf-ipsec-nat-t-ike-00 4485152D18B6BBCD0BE8A8469579DDCC ike 0:dc3556fc83a979ba/0000000000000000:10: VID DPD AFCAD71368A1F1C96B8696FC77570100 ike 0:dc3556fc83a979ba/0000000000000000:10: VID Fortinet Auto-Discovery Receiver CA4A4CBB12EAB6C58C57067C2E653786 ike 0:dc3556fc83a979ba/0000000000000000:10: VID Fortinet Exchange Interface IP A58FEC5036F57B21E8B499E336C76EE6 ike 0:dc3556fc83a979ba/0000000000000000:10: VID FRAGMENTATION 4048B7D56EBCE88525E7DE7F00D6C2D3 ike 0:dc3556fc83a979ba/0000000000000000:10: VID FRAGMENTATION 4048B7D56EBCE88525E7DE7F00D6C2D3C0000000 ike 0:dc3556fc83a979ba/0000000000000000:10: VID FORTIGATE 8299031757A36082C6A621DE00000000 ike 0:Test: ignoring IKE request, interface is administratively down ike 0:dc3556fc83a979ba/0000000000000000:10: negotiation failure ike Negotiate ISAKMP SA Error: ike 0:dc3556fc83a979ba/0000000000000000:10: no SA proposal chosen