3com WX3000 Manuel D’Utilisation

 

3-3 

contents). That is, the circuit ID or remote ID sub-option defines the type and length of a circuit ID or 

remote ID. 

The remote ID type field and circuit ID type field are determined by the option storage format. They are 

both set to “0” in the case of HEX format and to “1” in the case of ASCII format. 

Figure 3-2 Extended format of the circuit ID sub-option 

Suboption type

0

7

15

Length

Circuit ID type

Length

23

31

VLAN ID

Port Index

 

 

Figure 3-3 Extended format of the remote ID sub-option 

Suboption type

0

7

15

Length

Reomte ID type

Length

23

31

Bridge MAC Address

 

 

In practice, some network devices do not support the type and length identifiers of the Circuit ID and 

Remote ID sub-options. To interwork with these devices, the device supports Option 82 in the standard 

format. Refer to 

 for the standard format of the sub-options (with the default 

padding contents). In the standard format, the Circuit ID or Remote ID sub-option does not contain the 

two-byte type and length fields of the circuit ID or remote ID. 

Figure 3-4 Standard format of the circuit ID sub-option 

Suboption type

0

7

15

Length

23

31

VLAN ID

Port Index

 

 

Figure 3-5 Standard format of the remote ID sub-option 

Suboption type

0

7

15

Length

23

31

Bridge MAC Address

 

 

With DHCP snooping and DHCP-snooping Option 82 support enabled, when the DHCP snooping 

device receives a DHCP client’s request containing Option 82, it will handle the packet according to the 

handling policy and the configured contents in sub-options. For details, see 

.