74
UDP HELPER CONFIGURATION
When configuring UDP Helper, go to these sections for information you are
interested in:
■ “Introduction to UDP Helper” on page 927
■ “Configuring UDP Helper” on page 927
■ “Displaying and Maintaining UDP Helper” on page 928
■ “UDP Helper Configuration Example” on page 928
Introduction to UDP
Helper
Sometimes, a host needs to forward broadcasts to obtain network configuration
information or request the names of other devices on the network. However, if the
server or the device to be requested is located in another broadcast domain, the
host cannot obtain such information through broadcast.
To solve this problem, the device provides the UDP Helper function to relay
specified UDP packets. In other words, UDP Helper functions as a relay agent that
converts UDP broadcast packets into unicast packets and forwards them to a
specified destination server.
With UDP Helper enabled, the device decides whether to forward a received UDP
broadcast packet according to the UDP destination port number of the packet.
■ If the destination port number of the packet matches the one pre-configured
on the device, the device modifies the destination IP address in the IP header,
and then sends the packet to the specified destination server.
■ If not, the device sends the packet to the upper layer protocol for processing.
Configuring UDP
Helper
Follow these steps to configure UDP Helper:
To do… Use the command… Remarks
Enter system view system-view -
Enable UDP Helper udp-helper enable Required
Disabled by default.
Enable the forwarding of
packets with the specified
UDP destination port
number(s)
udp-helper port
{ port-number | dns |
netbios-ds | netbios-ns |
tacacs | tftp | time }
Required
By default, no UDP port
number is specified.
Enter VLAN interface view interface Vlan-interface
vlan-id
-
To Next Page
Loading...
