Not able to get traps for Firewalls and Network Devices

Hi I tried configuring trap based alerting , but somehow am not able to receive any kind of traps. On initial level we kept the Syslogs and Trap services disabled, but even after enabling the services I am not able to receive the traps.

I also validated if any firewall is there between the devices I monitor and my APE's. Not sure what can be done just to receive traps. Facing issues with also device types.

Regards

Himanshu Ranjan