Chapter 31 PPPoETable 101 PPPoE IA Remote ID Sub-option Format

SubOpt

Length

Value

 

 

 

0x02

N

MAC Address or String

(1 byte)

(1 byte)

(63 bytes)

 

 

 

The 1 in the first field identifies this as an Agent Circuit ID sub-option and 2 identifies this as an Agent Remote ID sub-option. The next field specifies the length of the field. The Switch takes the Circuit ID string you manually configure for a VLAN on a port as the highest priority and the Circuit ID string for a port as the second priority. In addition, the Switch puts the PPPoE client’s MAC address into the Agent Remote ID Sub-option if you do not specify any user-defined string.

31.1.2.1 Flexible Circuit ID Syntax with Identifier String and Variables

If you do not configure a Circuit ID string for a VLAN on a specific port or for a specific port, the Switch adds the user-defined identifier string and variables into the Agent Circuit ID Sub-option. The variables can be the slot ID of the PPPoE client, the port number of the PPPoE client and/or the VLAN ID on the PPPoE packet.

The identifier-string, slot ID, port number and VLAN ID are separated from each other by a pound key (#), semi-colon (;), period (.), comma (,), forward slash (/) or space. An Agent Circuit ID Sub- option example is “Switch/07/0123” and indicates the PPPoE packets come from a PPPoE client which is connected to the Switch’s port 7 and belong to VLAN 123.

Table 102 PPPoE IA Circuit ID Sub-option Format: Using Identifier String and Variables

SubOpt

Length

 

 

 

Value

 

 

 

 

 

 

 

 

 

 

 

 

0x01

N

Identifier

delimiter

Slot ID

delimiter

Port No

delimiter

VLAN ID

(1 byte)

(1 byte)

String

(1 byte)

(1 byte)

(1 byte)

(2 byte)

(1 byte)

(4 bytes)

(53 byte)

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

31.1.2.2 WT-101 Default Circuit ID Syntax

If you do not configure a Circuit ID string for a specific VLAN on a port or for a specific port, and disable the flexible Circuit ID syntax in the PPPoE > Intermediate Agent screen, the Switch automatically generates a Circuit ID string according to the default Circuit ID syntax which is defined in the DSL Forum Working Text (WT)-101. The default access node identifier is the host name of the PPPoE intermediate agent and the eth indicates “Ethernet”.

Table 103 PPPoE IA Circuit ID Sub-option Format: Defined in WT-101

SubOpt

Length

 

 

 

 

Value

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

0x01

N

Access

Space

eth

Space

Slot

/

Port No

:

VLAN

(1 byte)

(1 byte)

Node

(1

(3

(1

ID

(1

(2

(1

ID

Identifier

 

 

 

 

byte)

byte)

byte)

(1

byte)

byte)

byte)

(4

 

 

 

 

 

(20 byte)

 

 

 

byte)

 

 

 

bytes)

 

 

 

 

 

 

 

 

 

 

 

31.1.3 Port State

Every port is either a trusted port or an untrusted port for the PPPoE intermediate agent. This setting is independent of the trusted/untrusted setting for DHCP snooping or ARP inspection. You can also specify the agent sub-options (circuit ID and remote ID) that the Switch adds to PADI and PADR packets from PPPoE clients.

 

251

ES3500 Series User’s Guide