At the core of Ping Sweep is the ability to field ICMP communications. Depending on your network topology and speed, you may need to modify the ICMP Ping settings used by Ping Sweep.
Delay between PINGs: modify the time to wait before sending PING communication to each node. You can use this setting to limit traffic generated by Ping Sweep for slower connections.
PING Timeout: here you can adjust the amount of time that Ping Sweep waits for a response from a target IP address. If the target does not respond within the timeout and does not respond to any other PING attempts, it is assumed to be down.
PINGs transmitted per node: specify the number of PING attempts to send each address during a scan. When scanning networks that contain Cisco routers, set this number higher than two (2). If the target IP address is not in the ARP cache of a Cisco router, the router discards the ICMP query (PING) while it requests the MAC address of the target IP. The first PING will never arrive at the subnet of the target IP address. In this situation, the Cisco router responds to the second PING.
Packet Time-To-Live: the Packet Time-to-Live is the number of different locations you accept during the route to the IP address. A setting of 32 means your PING test could pass through up to 32 different routers on the way to the remote IP address before being thrown away by the network. Normally, you set this to 32 hops.