Is BRAS able to support STP?

Publication Date:  2012-09-12 Views:  203 Downloads:  0
Issue Description
Is BRAS able to support STP?
Alarm Information
None
Handling Process
To ensure the reliability of network in metropolitan area network, the switches are often used to build the ring network , and the STP protocol is used in the ring.  BRAS, as a key instrument in metropolitan area network, is a layer 3 instrument. BRAS can’t use the STP protocol, so BRAS can’t be used in the STP ring, the reliability of the network is reduced.
In fact, with the help of the transparent message of STP, the BRAS can joint in the STP ring without the support of STP protocol. In this situation, the BRAS is a HUB. 
As default, MA5200G isn’t configured the STP transparent line.
The configuration steps of the STP transparent line are as below:
STP-relay inport inport-type inport-number mac-address { mac-address | cisco-pvst+ | standard } outport outport-type outport-number mac-address { mac-address | cisco-pvst+ | standard }
After the configuration of the STP transparent line, MA5200G can judge the message in the entrance of the line, if the message is STP message; the STP message will be send to the exit directly.
MA5200G supports the MAC address of standard STP message (0180-C200-0000)and the MAC address in the format of PVST of STP message(0100-0CCC-CCCD), and also we can configure the MAC address manually.
We can configure 10 MAC address of STP message in the whole MA5200G system, get rid of the two addresses above, the user can configure 8 manually at most.
Root Cause
None
Suggestions
None

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