IPsec interface MTU value
IPsec interfaces may calculate a different MTU value after upgrading from 6.4.
This change might cause an OSPF neighbor to not be established after upgrading. The workaround is to set mtu-ignore to enable on the OSPF interface's configuration:
config router ospf
config ospf-interface
edit "ipsce-vpnx"
set mtu-ignore enable
next
end
end