3Com 3500 - Manual (Page 442)

442 C HAPTER 16: I NTERNET P ROTOCOL (IP)
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ip udpHelper display For CoreBuilder 9000: Applies to Layer 3 switching modules only.
Displays the BOOTP (bootstrap protocol) hop count and the threshold
configuration. Also lists the ports with their IP forwarding addresses that
are defined in your system.
Valid Minimum Abbreviation
ip u di
Important Considerations
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With UDP Helper, you can send User Datagram Protocol (UDP) packets
between routed networks. UDP Helper provides support for UDP
services such as BOOTP and DHCP (Dynamic Host Configuration
Protocol), which rely on the BOOTP relay agent.
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When you configure the logical BOOTP port, you can boot hosts
through the router. UDP Helper also provides a relay agent for DHCP
broadcasts. UDP packets that rely on the BOOTP relay agent are
modified and then forwarded through the router.
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BOOTP (including DHCP) uses UDP port 67.
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With UDP Helper, you can configure the amount of time that a UDP
packet is forwarded between subnetworks. The system discards UDP
packets based on the hop count and the seconds value only for
BOOTP and DHCP.
Fields in the IP udpHelper Display
Field Description
UDP port UDP port number — usually the value 67
Forwarding address Forwarding address that is used for UDP packets