Dell PowerSwitch S4128F-ON OS10 Enterprise Edition User Guide Release 10.4.1.0 - Page 488

Configuration parameters are options in the DHCP packet in type, length, value (TLV) format. To limit the number of parameters that servers must provide, hosts enter the parameters that they require and the server sends only those parameters. DHCP uses the User Datagram Protocol (UDP) as its transport protocol. Figure 6. DHCP Packet Format The table shows common options using DHCP packet formats. DHCP Option Description Subnet mask 1 - Subnet mask of the client Router 3 - Router IP addresses that serve as the default gateway for the client Domain name server 6 - Domain name servers (DNS) that are available to the client Domain name 15 - Domain name that clients use to resolve hostnames via DNS IP address lease time 51 - Amount of time that the client uses an assigned IP address DHCP message type 53: • 1 - DHCPDISCOVER • 2 - DHCPOFFER • 3 - DHCPREQUEST • 4 - DHCPDECLINE • 5 - DHCPACK • 6 - DHCPNACK • 7 - DHCPRELEASE • 8 - DHCPINFORM Parameter request list Renewal time Rebinding time Vendor class identifier User port stacking End 55 - Parameters the server requires for DHCP clients. This is a series of octets where each octet is a DHCP option code 58 - Amount of time, after the IP address is granted, that the client attempts to renew its lease with the original server 59 - Amount of time, after the IP address is granted, that the client attempts to renew its lease with any server, if the original server does not respond 60 - User-defined string the Relay Agent uses to forward DHCP client packets to a specific DHCP server 230 - Stacking option variable that provides the DHCP server stack-port details when the DHCP offer is set 255 - Signal of the last option in the DHCP packet 488 System management