Operation Manual – DHCPH3C S7500 Series Ethernet Switches Chapter 1 DHCP Overview1-51.4 DHCP Packet Processing ModesAfter the DHCP server is enabled on a device, the device processes the DHCP packetreceived from a DHCP client in one of the following three modes depending on yourconfiguration:z Global address pool: In response to the DHCP packets received from DHCPclients, the DHCP server picks IP addresses from its global address pools andassigns them to the DHCP clients.z Interface address pool: In response to the DHCP packets received from DHCPclients, the DHCP server picks IP addresses from the interface address poolsand assigns them to the DHCP clients. If there is no available IP address in theinterface address pools, the DHCP server picks IP addresses from its globaladdress pool that contains the interface address pool segment and assigns themto the DHCP clients.z Trunk: DHCP packets received from DHCP clients are forwarded to an externalDHCP server, which assigns IP addresses to the DHCP clients.You can specify the mode to process DHCP packets. For the configuration of the firsttwo modes, see DHCP Server Configuration. For the configuration of the trunk mode,see DHCP Relay Agent Configuration.One interface only corresponds to one mode. In this case, the new configurationoverwrites the previous one.1.5 Protocols and StandardsProtocol specifications related to DHCP include:z RFC2131: Dynamic Host Configuration Protocolz RFC2132: DHCP Options and BOOTP Vendor Extensionsz RFC1542: Clarifications and Extensions for the Bootstrap Protocol
