(Optional) Configuring IP Address Conflict Detection

IP address conflict detection uses ICMP to determine whether an IP address to be allocated conflicts with other IP addresses that are already allocated to clients. After this function is configured, a DHCP server sends an ICMP Echo Request message in which the source address is the IP address of the DHCP server and the destination address is the pre-allocated IP address for IP address conflict detection, before sending a DHCP Offer message to a client.

• If the DHCP server does not receive any ICMP Echo Reply message within the detection period (Number of detections x Maximum wait time for each conflict detection), this IP address is not used by any client. The DHCP server allocates the IP address to the client by sending a DHCP Offer message.
• If the DHCP server receives an ICMP Echo Reply message within the detection period (Number of detections x Maximum wait time for each conflict detection), this IP address is being used by a client. The DHCP server lists this IP address as a conflicting IP address and waits for the next DHCP Discover message to select another available IP address.

If the detection time is too long, clients may fail to obtain IP addresses. You are advised to set the detection time to less than 8 seconds.