Two front ports: nothing crosses in the switch, and the host's rules decide, 2026-10-25
Discovery 21 of the discoveries.
The vendor's TCAM sends every frame that comes in at a front port behind the switch to the
coprocessor, so two devices on two of those ports should never reach each other inside the switch.
Whether the host's rules then see what passes between them was left to be measured. The XGS 136 and
the second XGS 3300 are joined by two cables, each from a switch port to a switch port - the 3300's
Port6 to the 136's Port7, its Port8 to the 136's Port8 - so each board stood for the two devices
while the other was the board under test: the second XGS 3300 on SFOS 22's coprocessor software
(octep.ko 6cde3fde) and the XGS 136 on SFOS 21's (npuep.ko 590205fb)
(images/deploy/lab-frontports.sh, lab-frontports-136.sh, lab-tcam-read.sh).
The whole page, with how it was taken and what it does not show: Two front ports: nothing crosses in the switch, and the host's rules decide, 2026-10-25.
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