Nmap Host Detection throttle down

[Andres_Garcia]

Hi there, I am attempting to run an internal vulnerability scan down through a VPN on my Fortinet. There is a dynamic NAT in place that is forwarding the scan traffic from the VPN to the network I wish to scan (/24). If I specify the targets in my nmap command, the scan takes place without issues but if I try to discover what' s in the /24, the host detection part is taking an excessive amount of time (+7 hours). Does someone have an idea of what could might be throttling down the host detection process? Thanks!

[dasilva13]

Do you have any IPS polices in place?