Ip

An IPv4 default route is the prefix 0.0.0.0/0: it matches every IPv4 destination, with the least possible specificity. In a selected routing table, a longer matching prefix normally takes precedence. The default is not a procedure that retries whenever a more specific route fails. Routing policy selects relevant tables, and the chosen route describes a forwarding decision rather than promising that the entire round trip will succeed. ...

An IPv4 prefix length says how many leading address bits identify a network. For 192.0.2.5/24, the network is 192.0.2.0/24 and the ordinary broadcast address is 192.0.2.255. Configuring that interface commonly installs a connected route, but the prefix is not the entire routing algorithm. The kernel consults routing policy and route tables to select a path for each destination. ...

DHCP hands out leases with a duration, not perpetual ownership. The lifetime drives renewal and lets the server reclaim addresses the device no longer uses. Borrow a number, not own it DHCP does not give a device a permanent address; it lends one for a bounded time. On joining, a client broadcasts to discover a server, and the server offers an address with a lease lifetime defined by the network’s configured lease time. Because the assignment is temporary, the server always knows which addresses are valid and can track them in a pool without guessing. That temporary nature is what makes a large, frequently-changing network manageable: addresses are currency the server can hand out, extend, and take back, rather than addresses a host keeps forever. ...