Operation Manual – UDP HelperH3C S5500-EI Series Ethernet Switches Chapter 1 UDP Helper Configuration1-2To do… Use the command… RemarksSpecify the destinationserver to which UDPpackets are to beforwardedudp-helper serverip-addressRequiredNo destination server isspecified by default.Caution:z The UDP Helper enabled device cannot forward DHCP broadcast packets. That isto say, the UDP port number cannot be set to 67 or 68.z For the dns, netbios-ds, netbios-ns, tacacs, tftp, and time keywords, you canspecify port numbers or the corresponding parameters. For example, udp-helperport 53 and udp-helper port dns specify the same UDP port number.z The configuration of all UDP ports is removed if you disable UDP Helper.z You can configure up to 20 destination servers on a VLAN interface.1.3 Displaying and Maintaining UDP HelperTo do… Use the command… RemarksDisplays the informationof forwarded UDP packetsdisplay udp-helperserver [ interfaceVlan-interface vlan-id ]Available in any viewClear statistics aboutpackets forwarded reset udp-helper packet Available in user view1.4 UDP Helper Configuration ExampleI. Network requirementsThe interface VLAN-interface 1 of Switch A has the IP address of 10.110.1.1/16,connecting to the network segment 10.110.0.0/16. Enable the forwarding of broadcastpackets with the UDP destination port number 55 to the destination server 10.2.1.1/16.
