44 G8264 Application Guide for ENOS 8.4BOOTP/DHCP Client IP Address ServicesFor remote switch administration, the client terminal device must have a valid IPaddress on the same network as a switch interface. The IP address on the clientdevice may be configured manually, or obtained automatically using IPv6 statelessaddress configuration, or an IPv4 address may obtained automatically via BOOTPor DHCP relay as discussed in the next section.The G8264 can function as a relay agent for Bootstrap Protocol (BOOTP) or DHCP.This allows clients to be assigned an IPv4 address for a finite lease period,reassigning freed addresses later to other clients.Acting as a relay agent, the switch can forward a client’s IPv4 address request to upto five BOOTP/DHCP servers. In addition to the five global BOOTP/DHCP servers,up to five domain‐specific BOOTP/DHCP servers can be configured for each of upto 10 VLANs.When a switch receives a BOOTP/DHCP request from a client seeking an IPv4address, the switch acts as a proxy for the client. The request is forwarded as a UDPUnicast MAC layer message to the BOOTP/DHCP servers configured for theclient’s VLAN, or to the global BOOTP/DHCP servers if no domain‐specificBOOTP/DHCP servers are configured for the client’s VLAN. The servers respondto the switch with a Unicast reply that contains the IPv4 default gateway and theIPv4 address for the client. The switch then forwards this reply back to the client.DHCP is described in RFC 2131, and the DHCP relay agent supported on theG8264 is described in RFC 1542. DHCP uses UDP as its transport protocol. Theclient sends messages to the server on port 67 and the server sends messages to theclient on port 68.BOOTP and DHCP relay are collectively configured using the BOOTP commandsand menus on the G8264.DHCP Host Name ConfigurationThe G8264 supports DHCP host name configuration as described in RFC 2132,option 12. DHCP host name configuration is enabled by default.Host name can be manually configured using the following command:If the host name is manually configured, the switch does not replace it with thehost name received from the DHCP server.After the host name is configured on the switch, if DHCP or DHCP host nameconfiguration is disabled, the switch retains the host name.The switch prompt displays the host name.Host name configuration can be enabled or disabled using the followingcommand:RS G8264(config)# hostname RS G8264(config)# [no] system dhcp hostname
