is relative to the type of the switch, its current load and so on.
Example:Set the message transmission rate as 50pps
switch(Config)#ip dhcp snooping limit-rate 50
13.2.2.16 ip user helper-address
Command : ip user helper-address <svr_addr> [port <udp_port>] source
<src_addr> [secondary]
no ip user helper-address [secondary]
Function: Set the address and port of HELPER SERVER
Parameters:
<svr_addr>:the IP address of HELPER SERVER 的 IP in dotted-decimal notation.
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 Settings: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
13.2.2.17 show ip dhcp snooping
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