Digitalchina Networks DCS-3950 series User Manual

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DCS-3950 series Ethernet switch manual
udp_port：the UDP port of HELPER SERVER, the range of which is1－65535, and its
default value is 9119.
src_addr：the local management IP address of the switch, in dotted-decimal notation
sencondary：whether it is a secondary SERVER address.
Command mode：Globe Mode.
Default：There is no HELPER SERVER address by default.
Usage Guide：DHCP SNOOPING will send the monitored binding information to HELPER
SERVER to save it. If the switch starts abnormally, it can recover the binding data from
HELPER SERVER. The HELPER SERVER function usually is integrated into DCBI
package. The DHCP SNOOPING and HELPER SERVER use the UDP protocol to
communicate, and guarantee the arrival of retransmitted data. HELPER SERVER
configuration can also be used to sent DOT1X user data from the server, the detail
of usage is described in the chapter of ‘dot1x configuration’.
Two HELPER SERVER addresses are allowed, DHCP SNOOPING will try to connect to
PRIMARY SERVER in the first place. Only when the PRIMARY SERVER is unreachable,
will the switch c HELPER SERVER connects to SECONDARY SERVER.
Please pay attention：source address is the effective management IP address of
the switch, if the management IP address of the switch changes, this configuration
should be updated in time.
Example ： Set the local management IP address as 100.1.1.1, primary HELPER
SERVER address as 100.1.1.100 and the port as default value.
Switch(Config)#interface vlan 1
Switch(Config- If-Vlan1)#ip address 100.1.1.1 255.255.255.0
Switch(Config-If-Vlan1)exit
Switch(Config)#ip user helper-address 100.1.1.100 source 100.1.1.1
19.2.3 DHCP Snooping Typical Applications
Fig19-1 DHCP Snooping Typical Applications
As showed in the above picture, Mac-AA device is the normal user，connected to the

Digitalchina Networks DCS-3950 series Specifications

General

Brand	Digitalchina Networks
Model	DCS-3950 series
Category	Network Router
Language	English