Operation Manual – DHCPH3C S5600 Series Ethernet Switches Chapter 2 DHCP Server Configuration2-31Follow these steps to enable unauthorized DHCP server detection:To do… Use the command… RemarksEnter system view system-view —Enable the unauthorizedDHCP server detectingfunctiondhcp server detect RequiredDisabled by default.Note:With the unauthorized DHCP server detection enabled, the relay agent will log allDHCP servers, including authorized ones, and each server is recorded only once. Theadministrator needs to find unauthorized DHCP servers from the system loginformation.2.6.3 Configuring IP Address DetectingTo avoid IP address conflicts caused by assigning the same IP address to multipleDHCP clients simultaneously, you can configure a DHCP server to detect an IP addressbefore it assigns the address to a DHCP client.The DHCP server pings the IP address to be assigned using ICMP. If the server gets aresponse within the specified period, the server will ping another IP address; otherwise,the server will ping the IP addresses once again until the specified number of pingpackets are sent. If still no response, the server will assign the IP address to therequesting client (The DHCP client probes the IP address by sending gratuitous ARPpackets).Follow these steps to configure IP address detecting:To do… Use the command… RemarksEnter system view system-view —Specify the number ofping packetsdhcp server pingpackets numberOptionalTwo ping packets bydefault.Configure a timeoutwaiting for ping responsesdhcp server pingtimeout millisecondsOptional500 ms by default.
