Configuring Udp Helper - 3Com 4500 PWR 26-Port Configuration Manual

TACACS (Terminal Access Controller Access Control System)
TFTP (Trivial File Transfer Protocol)
Time Service

Configuring UDP Helper

Follow these steps to
To do...
Enter system view
Enable UDP Helper
Specify a UDP port number
Enable the UDP Helper TTL-keep
function
Enter VLAN interface view
Specify the destination server to
which the UDP packets are to be
forwarded
You need to enable UDP Helper before specifying any UDP port to match UDP broadcasts;
otherwise, the configuration fails. When the UD
ports are disabled, including the default ports.
The dns, netbios-ds, netbios-ns, tacacs, tftp, and time keywords correspond to the six default
ports. You can configure the default ports by specifying port numbers or the corresponding
parameters. For example, udp-helper port 53 and udp-helper port dns spe
You can specify up to 20 destination server addresses on a VLAN interface.
If UDP Helper is enabled after a destination server is configured for a VLAN interface, the
broadcasts from interfaces
to the destination server.
Protocol
configure UDP Hel per:
Use the command...
system-view
udp-helper enable
udp-helper port { port-number
dns | netbios-ds | ne
tacacs | tftp | time }
udp-helper ttl-keep enable
interface Vlan-interface vlan-id
udp-helper server ip-address
belonging to the VLAN and having a matching UDP port will be unicast
|
tbios-ns |
P helper function is disabled, all configured UDP
51-2
UDP port number
49
69
37
Remarks
—
Required
Disabled b y default.
Optional
By default, the device enabled with
UDP Helper forwards the
broadcast packets containing an
of the six port numbers 53, 138,
137, 49, 6 9 and 37.
Optional
Disabled by default. That is, UDP
Hel per does not forward IP
broadcasts with the TTL field being
1.
—
Required
No destinatio n server is specified
by default.
cify the same port.
y