Plumbing an IP address means what? What are some examples of it?
Essentially, it’s just another word for multi-homing a device, such as a server, with the caveat that it’s done on the same link rather than separate links. It’s generally a bad practice because multi-homing mostly accomplishes 2 things:
- It wastes IP addresses needlessly (in most cases)
- It creates a layer 2 security risk because you now have direct paths on multiple networks with typically no filtering (because most environments filter layer 3 but not layer 2), and because if anyone breaches that host they can now easily move laterally across the rest of the hosts on the same networks.