03-14-2013 08:56 AM - edited 03-07-2019 12:15 PM
Hello,
Sorry for my ignorance.
(1) I can understand this line in the command table :
All 0180.c200.0000 STATIC CPU
Whatever the VLAN number, all MAC frames carrying a BPDU do not enter the forwarding datase, they are blocked in this direction.
(2) I don't know why there is this line !
All ffff.ffff.ffff STATIC CPU
Normally, the broadcast address is permitted to enter the forwarding database.
Did I miss something?
Best regards,
Michel
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03-15-2013 05:00 AM
CPU needs to see broadcasts, for various reasons.
03-15-2013 05:51 AM
they are not blocked at all; those lines mean that frames destined to those MAC addresses are sent to the CPU to be processed there. Only the control plane is able to process BPDU's or other control plane protocols (i.e. ARP request sent to broadcast address need to be seen and processed by the CPU).
03-15-2013 05:00 AM
CPU needs to see broadcasts, for various reasons.
03-15-2013 05:51 AM
they are not blocked at all; those lines mean that frames destined to those MAC addresses are sent to the CPU to be processed there. Only the control plane is able to process BPDU's or other control plane protocols (i.e. ARP request sent to broadcast address need to be seen and processed by the CPU).
03-15-2013 08:42 AM
Hello Paolo and Riccardo,
I confused the filtering process described by IUT-T and by IEEE.
I agree, these 2 lines say that MAC frames with these DA address are sent to the CPU, that is the direction of the sublayers client of the MAC sublayer (according to the L/T field).
These lines don't say that :
- Frames wih DA = 01- 80-C2-00-00-00 are not forwarded (relayed to another port)
- Frames with DA = FF-FF-FF-FF-FF-FF are forwarded
It's different for ITU-T (G.8021). The filtering process block or pass the frames in the switching matrix. So, we don't have something similar to the second line.
Best regards,
Michel
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