heu, le 802.1p est partie intégrante du tag dans le 802.1q
Protocol Structure - VLAN: Virtual Local Area Network and the IEEE 802.1Q
IEEE 802.1Q Tagged Frame for Ethernet:
* TPID- defined value of 8100 in hex. When a frame has the EtherType equal to 8100, this frame carries the tag IEEE 802.1Q / 802.1P.
* TCI - Tag Control Information field including user priority, Canonical format indicator and VLAN ID.
* User Priority- Defines user priority, giving eight (2^3) priority levels. IEEE 802.1P defines the operation for these 3 user priority bits.
* CFI- Canonical Format Indicator is always set to zero for Ethernet switches. CFI is used for compatibility reason between Ethernet type network and Token Ring type network. If a frame received at an Ethernet port has a CFI set to 1, then that frame should not be forwarded as it is to an untagged port.
* VID- VLAN ID is the identification of the VLAN, which is basically used by the standard 802.1Q. It has 12 bits and allow the identification of 4096 (2^12) VLANs. Of the 4096 possible VIDs, a VID of 0 is used to identify priority frames and value 4095 (FFF) is reserved, so the maximum possible VLAN configurations are 4,094.
Message édité par dreamer18 le 20-10-2007 à 19:36:12
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"Parceque toi tu fracasses du migrant à la batte de baseball, c'est ça ?" - Backbone-