Black Box LGB6026A, Management Manual

Page: 1084 / 1289

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C
HAPTER
46 | IP Interface Commands
IPv4 Interface
NetBIOS Datagram Server port 138
NetBIOS Name Server port 137
NTP port 37
TACACS service port 49
TFTP port 69
C
OMMAND
M
ODE
Global Configuration
C
OMMAND
U
SAGE
Up to 100 UDP ports can be specified with this command for forwarding to
one or more remote servers.
E
XAMPLE
This example enables forwarding for DHCPv6 UDP packets.
Console(config)#ip forward-protocol udp 547
Console(config)#
ip helper
This command enables UDP helper globally on the switch. Use the no form
to disable this feature.
S
YNTAX
[ no ] ip helper
D
EFAULT
S
ETTING
Disabled
C
OMMAND
M
ODE
Global Configuration
C
OMMAND
U
SAGE
◆
Network hosts occasionally use UDP broadcasts to determine
information such as address configuration, and domain name mapping.
These broadcasts are confined to the local subnet, either as an all hosts
broadcast (all ones broadcast - 255.255.255.255), or a directed subnet
broadcast (such as 10.10.10.255). To reduce the number of application
servers deployed in a multi-segment network, UDP helper can be used
to forward broadcast packets for specified UDP application ports to
remote servers located in another network segment.
◆
To configure UDP helper, it must be enabled globally with the ip helper
command. The UDP destination ports for which broadcast traffic will be
forwarded must be specified with the
ip forward-protocol udp
command. And the remote servers which are configured to service UDP
clients on another network segment specified with the
ip helper-
address command.