I have three sites, Toronto (1.1.1.1), Mississauga (2.2.2.2) and San Francisco (3.3.3.3). All three sites have ASA 5520. All the sites are connected together with two site-to-site VPN links between each other location. My issue is that the tunnel between Toronto and San Francisco is very unstable, dropping every 40 min to 60 mins. The tunnel between Toronto and Mississauga (which is configured in the same manner) is fine with no drops. I also noticed that my pings with drop but the ASA thinks that the tunnel is still up and running. Here is the configuration of the tunnel. Toronto (1.1.1.1) crypto map Outside_map 1 match address Outside_cryptomap crypto map Outside_map 1 set peer 3.3.3.3 crypto map Outside_map 1 set ikev1 transform-set ESP-AES-256-MD5 ESP-AES-256-SHA crypto map Outside_map 1 set ikev2 ipsec-proposal AES256 group-policy GroupPolicy_3.3.3.3 internal group-policy GroupPolicy_3.3.3.3 attributes vpn-idle-timeout none vpn-tunnel-protocol ikev1 ikev2 tunnel-group 3.3.3.3 type ipsec-l2l tunnel-group 3.3.3.3 general-attributes default-group-policy GroupPolicy_3.3.3.3 tunnel-group 3.3.3.3 ipsec-attributes ikev1 pre-shared-key ***** isakmp keepalive disable ikev2 remote-authentication pre-shared-key ***** ikev2 local-authentication pre-shared-key ***** San Francisco (3.3.3.3) crypto map Outside_map0 2 match address Outside_cryptomap_1 crypto map Outside_map0 2 set peer 1.1.1.1 crypto map Outside_map0 2 set ikev1 transform-set ESP-AES-256-MD5 ESP-AES-256-SHA crypto map Outside_map0 2 set ikev2 ipsec-proposal AES256 group-policy GroupPolicy_1.1.1.1 internal group-policy GroupPolicy_1.1.1.1 attributes vpn-idle-timeout none vpn-tunnel-protocol ikev1 ikev2 tunnel-group 1.1.1.1 type ipsec-l2l tunnel-group 1.1.1.1 general-attributes default-group-policy GroupPolicy_1.1.1.1 tunnel-group 1.1.1.1 ipsec-attributes ikev1 pre-shared-key ***** isakmp keepalive disable ikev2 remote-authentication pre-shared-key ***** ikev2 local-authentication pre-shared-key ***** I'm at a loss. Any ideas?