====== Identification of L2 and L3 subscribers ======
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=====L3-subscribers=====
FastDPI 12 introduces support for identifying L2 subscribers by VLAN/Q-in-Q. 

Previously, the way of subscriber identification was only his MAC-address, which could lead to problems if two different subscribers belonging to different VLANs, have the same MAC-address.

FastDPI 12 introduces a new fastdpi.conf setting: ''bras_subs_id'', which is a type of L2 subscriber identification. It specifies a list, in order of preference, of what to consider to be the L2-subscriber ID. 

Valid values in the list:
  * ''mac'' -  The subscriber's MAC address (srcMAC of the packet from the subscriber) is the subscriber's identifier. This type is applicable to any network, including VLAN and Q-in-Q (VLANs are not counted).
  * ''vlan+mac'' - the subscriber identifier is the VLAN + subscriber's MAC. This type applies only to VLANs, but does not apply for Q-in-Q.
  * ''qinq'' - the subscriber identifier is Q-in-Q. Applicable for Q-in-Q networks only.
  * ''qinq+mac'' - subscriber identifier is Q-in-Q + subscriber's MAC. Applicable for Q-in-Q networks only.

The default value is ''bras_subs_id=mac'' (for compatibility with previous versions)

Setup example:
<code>
bras_subs_id=qinq+mac,vlan+mac,mac
</code>
is interpreted as follows:
  * If the packet is Q-in-Q - then the identifier is Q-in-Q + subscriber's MAC, 
  * otherwise if the package is VLAN - then the identifier is VLAN + subscriber's MAC,
  * otherwise the identifier is the subscriber's MAC.

Instead of a list you can set it to ''auto'':
<code>
bras_subs_id=auto
</code>

which is equal to:
<code>
bras_subs_id=qinq+mac,vlan+mac,mac
</code>
We recommend to use the ''auto'' value for ''bras_subs_id''.

If no identification type is defined for an incoming packet, then such subscriber is not terminated, all packets of the subscriber are dropped. This is possible for the following example:
<code>
bras_subs_id=qinq+mac
</code>
when the incoming packet from the subscriber is not Q-in-Q.

==== Radius Authorization ====

In the Radius L2 authorization request, the subscriber ID is passed in the VSA attribute ''VasExperts-L2-SubsId'' as a string:
<code>
ATTRIBUTE   VasExperts-L2-SubsId           14   string
</code>

The format of the string representation of the identifiers is as follows:
  * ''mac'': "[1]xx:xx:xx:xx:xx:xx", xx - subscriber's MAC address, e.g.: ''[1]02:42:89:33:7b:3e'' - subscriber MAC=02:42:89:33:7b:3e
  * ''vlan+mac'': "[2]N/xx:xx:xx:xx:xx:xx", N - VLAN number, e.g., ''[2]56/02:42:89:33:7b:3e'' - subscriber MAC=02:42:89:33:7b:3e в VLAN=56
  * ''qinq'': "[3]N.N", N - VLAN numbers, e.g.: ''[3]56.234'' - subscriber in Q-in-Q=56.234
  * ''qinq+mac'': "[4]N.N/xx:xx:xx:xx:xx:xx", e.g.: ''[4]56.234/02:42:89:33:7b:3e'' - subscriber MAC=02:42:89:33:7b:3e в Q-in-Q=56.234

If the subscriber's L2 identifier is unknown, then ''VasExperts-L2-SubsId=[0]<n/a>''.

=====L2-subscribers=====