FUCKUP #001: The VM That Could Reach Everything Except Its Gateway
The symptom A freshly installed Linux VM had a seemingly simple network problem. The VM was configured as: IP: 172.21.0.7/24 Gateway: 172.21.0.1 Another host on the same subnet was reachable: 172.21.0.7 -> 172.21.0.6 OK But the default gateway was not: 172.21.0.7 -> 172.21.0.1 FAIL So Layer 2 connectivity clearly existed — at least to other systems on the same network. What made it weird Packet captures made the situation even stranger. ...