Re:WiFi without internet on a Southwest flight
by AdamJacobMuller on Thursday September 28, 2023 @06:33PM
(#37696788)
> it was temperamental and didn't like any layer 2 "hiccups"
The clock was probably doing the "correct" thing when it got a TCP packet for a connection which it didn't recognize and sent back an RST, which caused the client to abort.
> kind of problems that teaches you to question your assumptions
Yep. I learned a lot from dealing with large layer-2 networks (commonly running on hardware not suited for the task). Mostly I learned to never run large L2 networks.
Fun anecdote from the early 2000's re: duplicate MACs:
Embedded IP time clock kept intermittently barfing out frames with the source MAC addresses of other devices on the network. The switch would update its MAC table and direct packets to this device. The Customer's AS/400 would kill all remote terminal sessions when the clock ended up w/ the AS/400's MAC. (They were doing a layer 2-based connection to the AS/400-- APPN, I believe it was called... Ugh, it was temperamental and didn't like any layer 2 "hiccups".)
MAC addresses flapping between ports is one of those "breaking the laws of physics" kind of problems that teaches you to question your assumptions. Gear with a crazy brain can do anything it wants to and it doesn't care about your assumptions.