PPPoE Intermediate Agent Configuration
476
Fig 56-2 PPPoE IA - vendor tag (4 bytes in each row)
Add TLV tag as 0x0105 for PPPoE IA, TAG_LENGTH is length field of vendor tag;
0x00000DE9 is ―ADSL Forum‖ IANA entry of the fixed 4 bytes; 0x01 is type field of Agent
Circuit ID, length is length field and Agent Circuit ID value field; 0x02 is type field of Agent
Remot ID, length is length field and Agent Remote ID value field.
PPPoE IA supplies a default circuit ID value, the default circuit ID (The figure in the
following) includes 5 fields, ANI (Access Node Identifier) can be configured by user, its
length is less than 47 bytes. If there is no ANI configured, MAC is accessed by default,
occupy 6 bytes and use space symbol to compart, ―eth‖ occupies 3 bytes and uses space
symbol to compart, ―Slot ID‖ occupies 2 bytes, use ―/‖ to compart and occupy 1 byte, ―Port
Index‖ occupies 3 bytes, use ―:‖ to compart and occupy 1 byte, ―Vlan ID‖ occupies 4 bytes,
all fields use ASCII, user can configure ciucuit ID for each port according to requirement.
ANI
(n byte)
Space
( 1byte)
eth
(3 byte)
Space
(1 byte)
Slot ID
(2 byte)
/
(1byte)
Port Index
(3 byte)
:
(1 byte)
Vlan ID
(4 byte)
Fig 56-3 Agent Circuit ID value
MAC of the access switch is the default remote ID value of PPPoE IA. remote ID
value can be configured by user flexibly, the length is less than 63 bytes.
56.1.2.4
Trust Port of PPPoE Intermediate Agent
Discovery stage sends five kinds of packets, PADI and PADR packets sent by client
to server, PADO and PADS packets sent by server to client, PADT packet can be sent by
server or client.
In PPPoE IA, for security and reduce traffic, set a port connected server as trust port,
set ports connected client as untrust port, trust port can receive all packets, untrust port