I just wanted to chime in here with a "me too"   Merak end: MX84, version 14.40 Cisco end: ASA 5585, version 9.8.4(10)   For two weeks i've been having to re-type a PSK on both Meraki and Cisco ASA side to get the tunnel to come back up.  My settings were:   IKE Policy: AES 256, SHA1, 86400 lifetime IPSEC Proposal: AES 256, SHA1, 86400 lifetime   Problem:  Tunnel drops right at 18 hours.   I had Meraki turn off NAT-T -- this did not fix the issue.   I then made the following changes:   IKE: 3DES, SHA1, lifetime 3600 IPSEC: 3DES, SHA1, lifetime 3600 NAT-T turned off still   Tunnel has been up for 20+ hours with no drop.  I'm assuming its the lifetime values and not the IKE/IPSEC proposals.  At any rate after struggling through this for weeks i'm happy it seems to be working better now.   Skip     ... View more