Layer 3 Routing Commands 1445configuration for the destination UDP port. If so, the relay agent unicasts thepacket to the configured server IP addresses. Otherwise the packet is notrelayed.The relay agent only relays packets that meet the following conditions:• The destination MAC address must be the all-ones broadcast address(FF:FF:FF:FF:FF:FF).• The destination IP address must be the IPv4 broadcast address(255.255.255.255) or a directed broadcast address for the receivinginterface.• The IP time-to-live (TTL) must be greater than 1.• The protocol field in the IP header must be UDP (17).• The destination UDP port must match a configured relay entry or an entryin Table 7-1.DHCP relay cannot be independently enabled or disabled globally. Only IPhelper can be enabled or disabled globally. Enabling IP helper enables DHCPrelay.Commands in this SectionThis section explains the following commands:bootpdhcprelay maxhopcount ip helper-address (global configuration)bootpdhcprelay minwaittime ip helper-address (interface configuration)clear ip helper statistics ip helper enableip dhcp relay information check show ip helper-addressip dhcp relay information check-reply show ip dhcp relayip dhcp relay information option show ip helper statisticsip dhcp relay information option-insert –
