Le 1/17/19 à 5:24 PM, Guy Harris a écrit : > On Jan 17, 2019, at 4:56 PM, Florian Fainelli <f.faine...@gmail.com> wrote: > >> These Ethernet adapters can be regular/normal Ethernet adapters, e.g: >> e1000e/igb/ixgbe on a PC connected to an Ethernet switch via GMII (for >> data path), and controlled by that PC through GPIO/SPI/I2C/MDIO for >> instance. If the switch is an external die/package then if you looked at >> frames between that NIC and the switch, you would see the tag, but that >> would require you snooping the wires between these two dies. If the >> switch is internal, things are not visible obviously. >> >> These Ethernet switch tags *never* go out to front-panel/RJ45 >> connectors, they remain within the Ethernet switch logic and get >> processed internally and stripped, and then regular Ethernet frames go >> out these RJ45 connectors, a similar operation applies in the other >> direction (ingress). > > OK, so it sounds as if: > > 1) the special ports on which the new DLT_ values would be used would > *always* get packets with the tags corresponding to the switch type, and > would *never* get regular Ethernet packets *or* DOCSIS packets from a Cisco > CMTS (Cable Modem Termination System); > > 2) regular Ethernet ports would *never* get packets with switch tags. > > If so, that means that that: > > 1) the special ports should have only *one* DLT_ value - the one > corresponding to the switch type; > > 2) other Ethernet ports should just get DLT_EN10MB and DLT_DOCSIS.
Correct. The other ports are exposed as regular Ethernet network devices. > >> OK, then requesting 10 DLT values, one per-tag is reasonable? > > Yes. I see that you answered on the pull request that I pasted the link for, thanks for doing that. Cheers -- Florian _______________________________________________ tcpdump-workers mailing list tcpdump-workers@lists.tcpdump.org https://lists.sandelman.ca/mailman/listinfo/tcpdump-workers
