736
C
HAPTER
67: UDP-H
ELPER
C
ONFIGURATION
c
CAUTION:
■
You need to enable the UDP-Helper function before specifying a UDP-Helper
destination port.
■
The
dns
,
netbios-ds
,
netbios-ns
,
tacacs
,
tftp
, and
time
keywords refers to
the six default UDP ports. You can configure a default port to be a UDP-Helper
destination port by specifying the corresponding port number or the
corresponding keyword. For example,
udp-helper port
53 and
udp-helper
port dns
specify the same port as a UDP-Helper destination port.
■
The
display current-configuration
command does not display the default
UDP ports that are configured to be UDP-Helper destination ports.
■
After UDP-Helper is disabled, all the configured UDP ports are cancelled,
including the default ports.
■
You can configure up to 20 destination servers on a VLAN interface.
■
If the destination server is configured on a VLAN interface, the UDP broadcast
packets received from the ports in the VLAN with specific UDP-Helper
destination ports are forwarded to the destination server configured on the
VLAN interface.
Displaying and
Maintaining
UDP-Helper
After performing the above configurations, you can use the
display
command in
any view to display the information about the destination servers and the number
of the packets forwarded to each destination server. Verify the configuration by
checking the output information. You can use the
reset
command in user view to
clear statistics about packets forwarded by UDP-Helper.
Configure a UDP port as a
UDP-Helper destination port
udp-helper port
{
port
|
dns
|
netbios-ds
|
netbios-ns
|
tacacs
|
tftp
|
time
}
This operation is unnecessary
if the port is among the
default UDP ports listed in
Table 591.
With UDP-Helper enabled,
UDP broadcast packets
destined for the ports listed in
Table 591 are relayed by
default.
Enter VLAN interface view
interface vlan-interface
vlan-id
-
Configure the destination
server to which the matched
UDP broadcast packets are to
be forwarded
udp-helper server
ip-address
Required
By default, no destination
server is configured
Table 592
Configure UDP-Helper
Operation Command Description
Table 593
Display and Maintain UDP-Helper
Operation Command Description
Display the information about
the destination servers and
the number of the packets
forwarded to each destination
server
display udp-helper server
[
interface vlan-interface
vlan-id
]
You can use the
display
command in any view
Summary of Contents for Switch 7754
Page 32: ...32 CHAPTER 1 CLI OVERVIEW ...
Page 70: ...70 CHAPTER 5 LOGGING IN USING MODEM ...
Page 76: ...76 CHAPTER 7 LOGGING IN THROUGH NMS ...
Page 86: ...86 CHAPTER 9 CONFIGURATION FILE MANAGEMENT ...
Page 120: ...120 CHAPTER 13 ISOLATE USER VLAN CONFIGURATION ...
Page 126: ...126 CHAPTER 14 SUPER VLAN ...
Page 136: ...136 CHAPTER 16 IP PERFORMANCE CONFIGURATION ...
Page 152: ...152 CHAPTER 17 IPX CONFIGURATION ...
Page 164: ...164 CHAPTER 19 QINQ CONFIGURATION ...
Page 172: ...172 CHAPTER 21 SHARED VLAN CONFIGURATION ...
Page 182: ...182 CHAPTER 22 PORT BASIC CONFIGURATION ...
Page 198: ...198 CHAPTER 24 PORT ISOLATION CONFIGURATION ...
Page 208: ...208 CHAPTER 25 PORT SECURITY CONFIGURATION ...
Page 224: ...224 CHAPTER 27 DLDP CONFIGURATION ...
Page 232: ...232 CHAPTER 28 MAC ADDRESS TABLE MANAGEMENT ...
Page 240: ...240 CHAPTER 29 CENTRALIZED MAC ADDRESS AUTHENTICATION CONFIGURATION ...
Page 280: ...280 CHAPTER 30 MSTP CONFIGURATION ...
Page 348: ...348 CHAPTER 35 IS IS CONFIGURATION ...
Page 408: ...408 CHAPTER 39 802 1X CONFIGURATION ...
Page 412: ...412 CHAPTER 40 HABP CONFIGURATION ...
Page 422: ...422 CHAPTER 41 MULTICAST OVERVIEW ...
Page 426: ...426 CHAPTER 42 GMRP CONFIGURATION ...
Page 480: ...480 CHAPTER 47 PIM CONFIGURATION ...
Page 506: ...506 CHAPTER 48 MSDP CONFIGURATION ...
Page 552: ...552 CHAPTER 51 TRAFFIC ACCOUNTING CONFIGURATION ...
Page 570: ...570 CHAPTER 53 HA CONFIGURATION ...
Page 582: ...582 CHAPTER 54 ARP CONFIGURATION SwitchA arp protective down recover interval 200 ...
Page 622: ...622 CHAPTER 58 DHCP RELAY AGENT CONFIGURATION ...
Page 684: ...684 CHAPTER 61 QOS CONFIGURATION ...
Page 718: ...718 CHAPTER 63 CLUSTER ...
Page 738: ...738 CHAPTER 67 UDP HELPER CONFIGURATION ...
Page 752: ...752 CHAPTER 69 RMON CONFIGURATION ...
Page 772: ...772 CHAPTER 70 NTP CONFIGURATION ...
Page 796: ...796 CHAPTER 72 FILE SYSTEM MANAGEMENT ...
Page 802: ...802 CHAPTER 73 BIMS CONFIGURATION ...
Page 814: ...814 CHAPTER 74 FTP AND TFTP CONFIGURATION ...
Page 830: ...830 CHAPTER 75 INFORMATION CENTER ...
Page 836: ...836 CHAPTER 76 DNS CONFIGURATION ...
Page 852: ...852 CHAPTER 77 BOOTROM AND HOST SOFTWARE LOADING ...
Page 858: ...858 CHAPTER 78 BASIC SYSTEM CONFIGURATION DEBUGGING ...