My Mac is unable to establish a VPN Tunnel to our VPN Server. My Windows Laptop can connect to the same endpoint. From the VPN Server Logs, the VPN Client is failing to respond to the heartbeat messages from the VPN Server during IKE Phase 2 negotiation. Typically, The IKE Negotiation begins on port 500 then rolls to port 4500 following the IPSec RFC Standards..
I've tried putting the Mac as the DMZ Host, no help. Tried going into the protocols and changing IPSec from Single Port 500 -> Single Port 500 to Any->Any, no help.
Does anyone at VZ have knowledge on how to resolve this?
Okay. Try disabling ALG in the gateway. Go to the Web UI of the router (usually http://192.168.1.1/ ) and log in. From there, select Advanced and locate a section labeled "ALG." Try turning the option for IPSec ALG off, or on respective to whether it was on or off when you found it.
Also, make sure the firewall is not set to anything higher than "Low". No security is the default setting and will work fine.