Users Guide

1242 Layer-2 and Layer-3 Relay Features
addresses. Otherwise, the relay agent verifies that there is a global configuration
for the destination UDP port. If so, the relay agent unicasts the packet to the
configured server IP addresses. Otherwise the packet is not relayed.
The relay agent relays packets that meet only 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 limited broadcast address
(255.255.255.255) or a directed broadcast address for the receive interface.
• 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.
NOTE: If the packet matches a discard relay entry on the ingress interface, the
packet is not forwarded, regardless of the global configuration.