Information - Juniper JUNOSE SOFTWARE FOR E SERIES 11.3.X - LINK LAYER CONFIGURATION GUIDE 2010-10-13 Configuration Manual

JunosE 11.3.x Link Layer Configuration Guide
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Bulk Configuration of VLAN Ranges Using Agent-Circuit-Identifier Information
Using bulk configuration to create S-VLAN IDs based on agent-circuit-identifier information
is similar to the process of creating a bulk-configured VLAN range that is not based on
agent-circuit-identifier information. However, when you issue the vlan bulk-config
command with the svlan-range keyword to specify the S-VLAN ID range, you then specify
the agent-circuit-identifier keyword instead of a VLAN ID range. This technique creates
a unique type of S-VLAN range in which the agent-circuit-identifier information is used
in place of the second tag.
The agent-circuit-identifier string is contained in the option 82 field of DHCP messages
for DHCP traffic, or in the DSL Forum VSA 26-1 of PPPoE PADR and PADI packets for
PPPoE traffic. The agent-circuit-identifier information identifies the subscriber's access
node and the DSL line on the access node. You can repeat the svlan-range and
agent-circuit-identifier keywords to provide nonoverlapping VLAN subranges that reside
within the VLAN range.
The following example configures a VLAN ID range made up of two subranges. The first
subrange configures S-VLANs 200–250 and the second subrange configures S-VLANs
3000–3500. Both subranges configure the subscriber identification based on
agent-circuit-identifier information.
host1(config)#interface gigabitEthernet 2/0
host1(config-if)#vlan bulk-config myAgent2BulkConfig svlan-range 200 250
agent-circuit-identifier svlan-range 3000 3500 agent-circuit-identifier
After you issue the vlan bulk-config command with the agent-circuit-identifier keyword,
the router provisions the S-VLAN IDs in the specified bulk-configured VLAN range at the
same time. The router does not dynamically create the VLAN subinterface until it receives
incoming data traffic. The user information is generated from the incoming data traffic
that contains the agent-circuit-identifier string.
Conceptually, a VLAN subinterface in this configuration has two attributes, an S-VLAN
ID and an agent-circuit-identifier string. This is analogous to a regular S-VLAN that also
has two attributes, an S-VLAN ID and a VLAN ID. However, the packet that the router
receives is singly-tagged with only a VLAN ID. The use of the agent-circuit-identifier
keyword in the vlan bulk-config command causes the router to further examine the
packet and extract the agent-circuit-identifier string in order to generate the subscriber
identification information.
In a DSL access network, subscriber information can be conveyed through either of the
following methods:
VLAN encapsulation; that is, the S-VLAN ID and the VLAN ID
Insertion of the agent-circuit-identifier string in DHCP or PPPoE messages
For example, the following configurations uniquely identify subscribers by means of VLAN
encapsulation:
Subscriber packets received from the DSLAM are single-tagged with a VLAN ID
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