Seitenhistorie

The circuit ID consists of five three fields. Note that the circuit ID in the switch is encoded in binary, but is expected by the router in hexadecimal notation. This can be seen in an Ethernet trace (filtered for BootP). For this reason the circuit ID must be prefixed with the string 0x. Furthermore, the VID and the port number must be converted if necessary. 

1. vlan_id: Stands for the VLAN ID of the switch port. The field has four digits, so the entry could be 000a 0010 for example.
2. module_id: Stands fo for the Module ID of the switch. Fo For GS-3xxx switches this is always 00.
3. port_no: Stands for the Port number of the switch port. The field has two digits, so the entry could be 07 for example.

Example:

A network member in VLAN 10 and connected to port 7 should be given a specific IP address. The VID 10 is in hexadecimal notation. The resulting circuit ID appears as follows: