My company has 2 ASA firewall with model 5510 & 5512 in difference country, I was connected it via IPSEC VPN. It can work in normal until 2 weeks ago.
I checked from log in ASA5512 firewall, it has error message :
Tunnel Manager has failed to establish an L2L SA. All configured IKE versions failed to establish the tunnel. Map Tag= outside_map. Map Sequence Number = 1.
And this message only display in ASA5512 and haven't alert in ASA5510. Also, the problem only affected specified tunnel only, remain other IPSEC VPN tunnel able to work properly.
show isakmp sa on both firewall it shows:
IKE Peer: [Firewall IP Address] Type : user Role : initiator Rekey : no State : MM_WAIT_MSG2
It look IKE phase 1 is unable to connect on each other.
Does anyone can advise on this issue?