Cover art for Back to the MAC

WPA3-KCIA Radio · Single

Back to the MAC

Jarrett Heintz · 3:20

  • Networking
  • Everything, A to Z
  • Wire & Packet
Play on WPA3-KCIA Radio

Lyrics

  1. Okay class, breathe in deep.
  2. Layer two is not asleep.
  3. Not Mandatory Access Control, calm down.
  4. Not fruit computers in a turtleneck gown.
  5. We are talking frames on the wire.
  6. Copper, fiber, little sparks of fire.
  7. I-P address tells you WHERE.
  8. Across the net, across the air.
  9. Logical map, routed through.
  10. Hops and tables pushing you.
  11. Subnets, masks, default gate.
  12. Packets travel state to state.
  13. I-P is destination plan.
  14. City and street on the diagram.
  15. But when that packet hits the switch, We need more detail for the stitch.
  16. Because inside this local rack, Delivery needs a MAC.
  17. Layer three says where to go. Layer two says who I know. Do not blend them, do not slip. One is hardware, one is trip.
  18. MAC Address but why I-P?
  19. This other stuff confuses me.
  20. To get delivered I-P is WHERE, What I need if it is not shared.
  21. M-A-C is WHO, which N-I-C or blue?
  22. It is how we give the switch a clue.
  23. Keep the difference clear and sharp.
  24. That is why the network seal says ARP.
  25. Switch looks down at frame header.
  26. Forty eight bits, now we are better.
  27. Burned in code from factory line.
  28. Globally unique by design.
  29. First half vendor, O-U-I.
  30. Second half identity.
  31. No routing brain, no grand tour.
  32. Just local segment, nothing more.
  33. Router reads the I-P scheme. Finds next hop in routing stream. Encapsulate and send it back. Wrap that packet in a MAC.
  34. One is logical, one is steel.
  35. One can change, one feels more real.
  36. But even hardware can be spoofed.
  37. Security class, stay aloof.
  38. MAC Address but why I-P?
  39. This other stuff confuses me.
  40. To get delivered I-P is WHERE, What I need if it is not shared.
  41. M-A-C is WHO, which N-I-C or blue?
  42. It is how we give the switch a clue.
  43. Keep the difference clear and sharp.
  44. That is why the network seal says ARP.
  45. How does layer two learn the map?
  46. Broadcast shout across the app.
  47. Who has ten dot zero dot five?
  48. Tell me quick so I survive.
  49. Reply comes back, do not harp.
  50. Resolution time with ARP.
  51. Cache it now so we are fast.
  52. Table built, confusion passed.
  53. Back to the M-A-C.
  54. Not Mandatory Access Control policy.
  55. Not shiny laptops sipping tea.
  56. Just hardware tags for delivery.
  57. Back to the M-A-C.
  58. Frames on the wire in front of me.
  59. If I-P is city and street, M-A-C is the house you meet.
  60. MAC Address but why I-P?
  61. Now it is less confusing me.
  62. I-P is WHERE across the sea.
  63. M-A-C is WHO locally.
  64. Keep them separate, crisp and sharp.
  65. Seal the concept with ARP.
  66. Layer three and layer two.
  67. Different jobs, both are true.
  68. If timing slips, that is okay.
  69. Packets still will find their way.
  70. Back to the M-A-C we go.
  71. Now the difference runs the show.