3Com 5500-EI PWR, Справочное руководство

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z
Enable DHCP-snooping and DHCP-snooping Option 82 before performing this configuration.
z
If a handling policy is configured on a port, this configuration overrides the globally configured
handling policy for requests received on this port, while the globally configured handling policy
applies on those ports where a handling policy is not natively configured.
Examples
# Configure the keep handling policy for DHCP requests that contain Option 82 on the DHCP snooping
device.
<Sysname> system-view
System View: return to User View with Ctrl+Z.
[Sysname] dhcp-snooping information strategy keep
dhcp-snooping information vlan circuit-id
Syntax
dhcp-snooping information [ vlan vlan-id ] circuit-id string string
undo dhcp-snooping information { [ vlan vlan-id ] circuit-id | circuit-id all }
View
Ethernet port view
Parameters
vlan vlan-id : Specifies a VLAN. DHCP packets from the VLAN are padded with the circuit ID
sub-option.
string : Content of the circuit ID sub-option, a string of 3 to 63 ASCII characters.
Description
Use the dhcp-snooping information vlan circuit-id command to configure the content of the circuit
ID field in Option 82.
Use the undo dhcp-snooping information circuit-id command to restore the default.
With vlan vlan-id specified, the customized circuit ID sub-option applies only to the DHCP packets from
the specified VLAN. With no vlan vlan-id specified, the customized circuit ID sub-option applies to all
DHCP packets that pass through the current port.
Use the undo dhcp-snooping information vlan vlan-id circuit-id command to restore the default
circuit ID in DHCP packets from the specified VLAN.
Use the undo dhcp-snooping information circuit-id command to restore the default circuit ID for all
DHCP packets except those from the specified VLAN.
Use the undo dhcp-snooping information circuit-id all command to restore the default circuit ID for
all DHCP packets.
By default, the circuit ID field in Option 82 contains the VLAN ID and index of the port that received the
client’s request.