ZyXEL Communications OLT2406 User Manual page 253

example is "OLT/07/0123" and indicates the PPPoE packets come from a PPPoE client which is
connected to the OLT's port 7 and belong to VLAN 123.
Table 98 PPPoE IA Circuit ID Sub-option Format: Using Identifier String and Variables
SubOpt
0x01
(1 byte)
29.1.2.4 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 OLT 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 99 PPPoE IA Circuit ID Sub-option Format: Defined in WT-101
SubOpt
0x01
(1 byte)
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 OLT adds to PADI and PADR packets from
PPPoE clients.
Trusted ports are connected to PPPoE servers.
• If a PADO (PPPoE Active Discovery Offer), PADS (PPPoE Active Discovery Session-confirmation), or
PADT (PPPoE Active Discovery Terminate) packet is sent from a PPPoE server and received on a
trusted port, the OLT forwards it to all other ports.
• If a PADI or PADR packet is sent from a PPPoE client but received on a trusted port, the OLT forwards it
to other trusted port(s).
Note: The OLT will drop all PPPoE discovery packets if you enable the PPPoE intermediate
agent and there are no trusted ports.
Untrusted ports are connected to subscribers.
• If a PADI, PADR, or PADT packet is sent from a PPPoE client and received on an untrusted port, the OLT
adds a vendor-specific tag to the packet and then forwards it to the trusted port(s).
• The OLT discards PADO and PADS packets which are sent from a PPPoE server but received on an
untrusted port.
Length
N Identifier delimiter
String
(1 byte) (1 byte)
(53 byte)
Length
N Access Spac
Node e
(1 byte)
Identifier
(1
(20 byte) byte)
OLT2406 User's Guide
Chapter 29 PPPoE
Value
Slot ID delimiter
(1 byte) (1 byte)
Value
eth Spac Slot ID
e
(3 (1
byte) (1 byte)
byte)
253
Port No delimiter VLAN ID
(2 byte) (1 byte) (4 bytes)
/ Port No : VLAN ID
(1 (2 byte) (1 (4
byte) byte) bytes)