Juniper JUNOSE 11.1.X - LINK LAYER CONFIGURATION 4-7-2010, Руководство по настройке

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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
664 ■
Configuring VLAN Dynamic Subinterfaces
JUNOSe 11.1.x Link Layer Configuration Guide