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Inner VLAN tag -> S-Tag The current protocol specification requires that the inner VLAN tag be a Q-Tag (official a “C-Tag” now). S-Tag is more expressive for QoS. Only 1 bit different between Q and S tags: “Canonical Format Indicator” for Q-tags, “Drop Eligible Indicator” for S-tags. Current spec says CFI = 0 in inner tag. Inner VLAN tag is only seen by TRILL knowledgeable devices. Inner Tag priority and VLAN ID typically constructed at ingress RBridge. Suggest using S-Tag so the DEI would be available. |