We recently upgraded our branch office SRX650 firmware from 10.2.3 to 10.4.3 a couple of weeks ago. Afterwards we've seen VPN tunnels flap up and down on LAN side. During which the WAN side never goes down. Funny thing is when you login into one of the SRX220 you do show interfaces terse the LAN side shows up/up.
We have site to site VPN tunnels from our branch SRX650s to field SRX220s.
I've tried rebooting the SRX220's, lowering tcp-mss and ipsec-vpn from 1300 to 1360 but to no avail. My SRX650 CPU utilization is low. The monitoring software I'm using to monitor the tunnels test time has been upped to test less frequent to no avail.
We have plenty of other VPN tunnels on the SRX650 that aren't flapping. I'm kind of lost and need some help.