dhcp snooping information circuit-id
Use dhcp snooping information circuit-id to configure the padding mode and padding format for the Circuit ID sub-option.
Use undo dhcp snooping information circuit-id to restore the default.
Syntax
dhcp snooping information circuit-id { [ vlan vlan-id ] string circuit-id | { normal | verbose [ node-identifier { mac | sysname | user-defined node-identifier } ] } [ format { ascii | hex } ] }
undo dhcp snooping information circuit-id [ vlan vlan-id ]
Default
The padding mode is normal and the padding format is hex.
Views
Layer 2 Ethernet interface view
Layer 2 aggregate interface view
Predefined user roles
network-admin
mdc-admin
Parameters
vlan vlan-id: Pads the Circuit ID sub-option for packets received from the specified VLAN. If you do not specify a VLAN, the device pads the Circuit ID sub-option for packets received from the default VLAN.
string circuit-id: Specifies the string mode, in which the padding content for the Circuit ID sub-option is a case-sensitive string of 3 to 63 characters.
normal: Specifies the normal mode. The padding content includes the VLAN ID and interface number.
verbose: Specifies the verbose mode. The padding content includes the node identifier, interface information, and VLAN ID. The default node identifier is the MAC address of the access node. The default interface information consists of the Ethernet type (fixed to eth), chassis number, slot number, sub-slot number, and interface number.
node-identifier { mac | sysname | user-defined node-identifier }: Specifies the access node identifier.
mac: Uses the MAC address of the access node as the node identifier.
sysname: Uses the device name as the node identifier. You can set the device name by using the sysname command in system view. The padding format for the device name is always ASCII regardless of the specified padding format.
![[NOTE: ]](images/note.png) | NOTE: If sysname is specified as the node identifier, do not include any spaces when you set the device name. Otherwise, the DHCP snooping device fails to add or replace Option 82. | |
user-defined node-identifier: Uses a case-sensitive string of 1 to 50 characters as the node identifier. The padding format for the specified character string is always ASCII regardless of the specified padding format.
format: Specifies the padding format for the Circuit ID sub-option.
ascii: Specifies the ASCII padding format.
hex: Specifies the hex padding format.
Usage guidelines
The Circuit ID sub-option cannot carry information about interface splitting or subinterfaces. For more information about interface splitting and subinterfaces, see Interface Configuration Guide.
If you execute this command multiple times, the most recent configuration takes effect.
The padding format for the string mode, the normal mode, or the verbose mode varies by command configuration. Table 18 shows how the padding format is determined for different modes.
Table 18: Padding format for different modes
Keyword (mode) | If no padding format is set | If the padding format is ascii | If the padding format is hex |
|---|---|---|---|
string circuit-id | The padding format is always ASCII, and is not configurable. | N/A | N/A |
normal | Hex. | ASCII. | Hex. |
verbose | Hex for the VLAN ID. ASCII for the node identifier, Ethernet type, chassis number, slot number, sub-slot number, and interface number. | ASCII. | ASCII for the node identifier and Ethernet type. Hex for the chassis number, slot number, sub-slot number, interface number, and VLAN ID. |
Examples
# Configure verbose as the padding mode, device name as the node identifier, and ASCII as the padding format for the Circuit ID sub-option.
<Sysname> system-view [Sysname] interface [Sysname-] dhcp snooping information enable [Sysname-] dhcp snooping information strategy replace [Sysname-] dhcp snooping information circuit-id verbose node-identifier sysname format ascii
Related commands
dhcp snooping information enable
dhcp snooping information strategy
display dhcp snooping information