3Com 5500 SI - Switch - Stackable, Configuration Manual

Page: 304 / 686

304 C
HAPTER
17: N
ETWORK
P
ROTOCOL
O
PERATION
Perform the following configuration in System View.
Note that
:
■
You must first enable the UDP Helper function and then configure the UDP port
with the relay function. Otherwise, error information will appear.
■
The parameters
dns , netbios-ds , netbios-ns , tacacs , tftp
and
time
respectively refer to the six default ports. You can configure the default UDP port
in two ways: specifying port IDs and specifying the correct parameters. For
example, the
udp-helper port 53
command is equivalent to the
udp-helper
port dns
command in function.
■
The default UDP ports are not displayed when using the
display
current-configuration
command. But its ID is displayed after its relay function
is disabled.
Configuring the Relay Destination Server for Broadcast Packet
You can configure up to 20 relay destination servers for a VLAN interface. If a VLAN
interface is configured with relay destination servers and UDP Helper function is
enabled on the VLAN interface, then the broadcast packets of a designated UDP port
received at the VLAN interface will be unicasted to the destination server.
Perform the following configuration in VLAN Interface View.
Note that:
■
The
undo udp-helper server
command (without any parameter) deletes all
destination servers configured on the interface.
■
By default, no relay destination server for UDP broadcast packets is configured.
NetBIOS Name Service (NetBIOS-NS) 137
NetBIOS Datagram Service (NetBIOS-DS) 138
Terminal Access Controller Access Control System (TACACS) 49
Table 301 Configuring UDP Port with Replay Function
Operation Command
Configure UDP port with
replay function
udp-helper port
{
port
|
dns
|
netbios-ds
|
netbios-ns
|
tacacs
|
tftp
|
time
}
Remove the configuration
undo udp-helper port
{
port
|
dns
|
netbios-ds
|
netbios-ns
|
tacacs
|
tftp
|
time
}
Table 302 Configuring the Relay Destination Server for Broadcast Packet
Operation Command
Configure relay destination server for
broadcast packet
udp-helper server ip_address
Delete relay destination server for
broadcast packet
undo udp-helper server
[
ip_address
]
Table 300 Default UDP Ports List
Protocol UDP port ID